OATD is one of the best starting points for finding open-access graduate theses and dissertations from around the world, indexing millions of records from universities across dozens of countries. Unlike some countries that maintain a single national register, there is no one global database for all theses. This guide walks you through the main resources available, how to search them effectively, and how to use what you find when writing your own thesis or dissertation.
Why there is no single global register
Academic institutions differ in how they handle thesis publication. Some countries have a centralized national register: Slovakia runs CRZP, the Czech Republic operates Theses.cz, Germany collects doctoral dissertations through the Deutsche Nationalbibliothek. In most English-speaking countries, however, universities manage their own institutional repositories. The result is a distributed landscape: no single database covers everything, but a handful of aggregators make the search manageable.
Major databases and where to find them
OATD: Open Access Theses and Dissertations
OATD aggregates metadata from more than 1,100 universities and research institutions worldwide, indexing millions of theses. The full text stays on each university's own repository; OATD provides the searchable index. You can filter by language, institution, and date. Because records come via OAI-PMH harvesting, coverage depends on whether a given university has made its repository open.
NDLTD: Networked Digital Library of Theses and Dissertations
NDLTD Global ETD Search is one of the older aggregators, supported by an international consortium of libraries and universities. It covers theses from North America, Europe, and beyond, with links to full text where available. Worth checking alongside OATD, as the two services do not always index the same records.
BASE: Bielefeld Academic Search Engine
BASE is a broad open-access search engine run by Bielefeld University Library, covering academic repositories globally. Theses and dissertations appear among other scholarly outputs. Useful when you want to combine thesis searches with journal articles and conference papers in one query.
CORE
CORE aggregates research papers and theses from open repositories worldwide and provides full-text search. It is particularly strong for UK and European institutions. The platform also offers API access for systematic research.
ProQuest Dissertations and Theses (commercial)
ProQuest is the largest commercial database of dissertations and theses, with coverage going back to the 19th century for North American institutions. Access requires an institutional subscription. If your university library subscribes, ProQuest is often the most comprehensive source for North American doctoral work.
EThOS: British Library (UK)
EThOS is the British Library's e-theses service, holding records for over 600,000 UK doctoral theses. At the time of writing, the service has been offline following a cyber-attack on the British Library in October 2023. An interim platform was expected to launch in mid-to-late June 2026, which will provide searchable records and link to university repositories but will not initially offer direct file downloads. Check the British Library's official status page before relying on EThOS. As an alternative, search the awarding university's own repository directly.
How to search effectively
Search by title or author
All major aggregators support keyword search across titles and author names. Use both the full name and abbreviations when searching for authors. For titles, try variations: a thesis registered as "Digital Marketing in SMEs" may also appear under "Online Marketing for Small Businesses."
Search by abstract and keywords
OATD and BASE both index abstracts, which dramatically improves relevance. Use subject-specific terminology, and try both the language of the country you are searching and English equivalents. Boolean operators (AND, OR, NOT) help narrow or expand results.
Filter by institution, country, or degree type
Most platforms let you restrict results by awarding institution, country, or degree type (master's vs. doctoral). Use these filters when you want to compare practices at specific universities or focus on a particular academic tradition.
What you see in a record
A typical thesis record includes:
- author name
- full title
- awarding institution and department
- supervisor name (in some records)
- year of award
- degree type
- abstract
- subject keywords
- link to full text (if open access)
Why full text is sometimes unavailable
Open access is not universal. An author may have chosen to restrict access to their thesis, for example, because they plan to publish it as a book or because it contains sensitive data. Some universities make only the metadata public. In these cases:
- check the awarding university's institutional repository directly
- contact the university library, which may be able to facilitate access
- look for a published journal article or book that grew out of the thesis
The relationship between thesis databases and plagiarism detection
National registers like CRZP and Theses.cz feed directly into plagiarism detection systems used by universities. When you submit your own thesis, it will be checked against these databases. This is relevant for you as a writer: if you draw on an existing thesis, cite it properly. Undisclosed paraphrasing from a registered thesis is just as detectable as copying from a published article. See our article on plagiarism check and originality for details on how detection works.
How to use thesis databases when writing your own work
Check whether your topic is already heavily covered
Search your proposed topic in OATD or NDLTD before committing to it. If dozens of near-identical dissertations exist, you need to differentiate your research question. For guidance on choosing a topic that stands out, see How to choose your thesis topic.
Study structure and methodology
Reading abstracts and, where available, full texts of successful theses in your field shows you how researchers structure chapters, formulate research questions, and present findings. This gives a realistic picture of disciplinary norms. Our guide on how to structure a thesis covers the main conventions in detail.
Build your reference list
Thesis bibliographies are goldmines. A dissertation on your topic will point you to monographs, articles, and datasets that you might not find through a standard database search. Once you have those sources, cite them correctly using ISO 690 citation guidelines.
Understand the scope of existing knowledge
Reading a cluster of theses in your area helps you map what is already known, which debates are unresolved, and where genuine gaps exist. This is the foundation of a solid literature review.
FAQ
Is OATD free to use?
Yes, OATD is free and requires no registration. It indexes theses that are openly available, so the linked full texts are also free to read. For paywalled or restricted theses, you need access through a library.
Does OATD cover theses from Europe and Asia?
Yes. OATD harvests metadata from institutions worldwide, including Europe, North America, Australia, and parts of Asia. Coverage depends on whether each institution's repository has OAI-PMH harvesting enabled and is registered with OATD.
Can I find master's theses, or only doctoral dissertations?
Both. OATD, NDLTD, and CORE all index master's theses alongside doctoral dissertations. ProQuest also covers both, with slightly better coverage of North American master's work.
What should I do if the full text is not available?
First, check the awarding university's own repository or library catalogue. If the thesis is digitised but restricted, contact the library directly. Some libraries offer interlibrary loan or can facilitate contact with the author. For UK theses, individual university repositories are currently the main access point while EThOS is being restored.
Are there country-specific alternatives to OATD?
Yes. Slovakia has CRZP, the Czech Republic has Theses.cz, Germany has DissOnline via the Deutsche Nationalbibliothek, and France and other countries have their own national registers. Country-specific databases often have deeper coverage of local institutions than international aggregators.
Does searching these databases help me avoid plagiarism in my own work?
Searching thesis databases tells you what exists, which helps you write an original contribution. But actual plagiarism checking at your institution uses specialised software. These are complementary activities, not the same thing.
Conclusion
Finding existing theses and dissertations requires knowing which databases to use and how to combine them. OATD is a solid starting point for open-access work from global institutions; NDLTD and BASE complement it with broader coverage; ProQuest is the strongest option if your library subscribes; and national registers like CRZP and Theses.cz offer deeper coverage within their respective countries. Use these resources not just to check whether your topic has been done before, but as a genuine research tool that improves the quality of your literature review and argument.