This paper discusses the phycological research and gives a historical overview of papers dealing with macroalgae from the East African coast. A review of the recent progress towards a marine algal flora of the region is presented. Additionally a limited number of taxonomic problems are discussed, with emphasis on examples from Tanzania and Zanzibar. Problems comprise generic, specific and subspecific distinctions, perpetuation of wrong identifications from ‘reference works’, and check-lists with doubtful identifications that lack voucher specimens. Finally a list of 91 new species for Kenya (23), Tanzania (24), the East African coast (26) and the Indian Ocean (18) is added. HISTORY