An excellent list of electronic and print lists of dissertations is found on the Africa South of the Sahara web site. Some of the more important titles:
ASA News, "Recent Doctoral Dissertations" - by Joseph J. Lauer and others.
Until mid-2009, each issue of the African Studies Association (U.S.) newsletter, ASA News, carried a list, by subject, of recent American, Canadian, and U. K. dissertations. No longer published in ASA News but list is available digitally.
American Historical Association. Directory of Dissertations in Progress
Database of dissertations in progress in the U.S. and Canada. Dissertations are submitted by the university department.
Center for Research Libraries (CRL). Foreign Dissertations Database
CRL seeks to collect dissertations from outside the U.S. and Canada. New acquisitons are found though the CRL catalog but CRL's Foreign Doctoral Dissertations Database provides access to a large collection that has not been cataloged. This database is not beng updated..NOTE CRL has announced that all foreign dissertations have been cataloged and added to the CRL catalog.
DART, access to european dissertations.
Dissertations & Theses (formerly Dissertaion Abstracts) at ProQuest
Covers dissertations accepted at accredited U.S. institutions since 1861. Approximately 47,000 new dissertations and 12,000 new theses to the database each year. It selectively covers masters theses, Canadian dissertations, British, and other international dissertations. Abstracts are included for dissertations beginning July 1980 and for masters theses beginning spring 1988. Many dissertations are available for free download for Emory users.
A new effort by the British Library to provide a single hub for theses produced by a number of British institutions of higher education. Currently over 100 universities are participating including School of Oriental and African Studies. For a current list of participating institutions click here. Some dissertations are available for free download but others require purchase.
NOTE: Most major universities now have electronic depositories to house their graduates' dissertations. This includes major African univerisities as well, e.g. Wits' WiredSpace.