In the Phycological Departament of the W. Szafer Institute of Botany, Polish Academy of Sciences in Cracow, material essential for the proper assignment of the algal flora found in Poland have been gathered. Among them is the collection of original publications and separata (or their copies) concerning the contemporary and fossil algae as well as the bibliography on the Polish algal flora. On this basis, the indices of taxa found in Poland belonging to all prokaryotic and eukaryotic systematic groups of algae, initially in the form of files, now stored on computers, are elaborated. After publication of the bibliographies (Sieminska 1990, Sieminska and Pajak 1995), successive indices will be issued. The one concerning the blue-green algae mentioned in literature up to 1980 has already been published (Sieminska 1995), a continuation (up to 1990) is already for print and so is the fascicle concerning diatoms (total, up to 1990). Each index contains the list of Latin names of the genera and species given in alphabetical order. Latin names of the lower systematic units are placed below, also alphabetically, irrespective of their rank. The names of author (authors) usually written next to the Latin of a taxon are omitted because of the fact that they are very often inconsistently cited and sometimes concern different taxa. The taxon name is followed by the numbers of the references in which it has been mentioned in the bibliographies. Next to each number, the symbol of the kind of information is given (in parentheses); drawings and photos, i.e. illustrations (i), complementary remarks concerning size or morphology (u), and description (n) of the new taxon. The data which have been elaborated diligently for more than 40 years thus far and the published indices create a base facilitating floristic and physiographic studies as well as the preparation of monographs, till now non-existing, on the representatives of particular systematic groups of contemporary and fossil algae in Poland. For the phycologists from other countries, the indices provide information on the components of Polish flora, in particular the rarely occurring taxa. The subsequent fascicles will be published - similarly as the first one - simultaneously in English and Polish. The indices, as well as the bibliographies, may be purchased at the publisher office, which is the W. Szafer of Botany P.A.Sc., Cracow, Lubicz 46.