The African Regional Centre for Technology, in collaboration with the African Academy of Sciences and the Carnegie Corporation, has produced this guide as part of the Centre's work to reduce difficulties encountered in the search for information, to evaluate directories on Africa, and to provide data on research and development institutions in a major systematic and centralised form. A total of 242 directories were analysed. Consecutively numbered, entries cover 85 international directories, 59 directories on Africa, 22 regional directories on North Africa and 76 regional directories on sub-Saharan Africa. Each entry includes title, publisher, address, editors, descriptors, date of publication, number of edition, languages and other bibliographic information, together with a summary and short review of contents. Access is by four indexes: authors and compilers or scientific editors, publishers, geographical zones and subjects.