Summary The international symposium “Biology and Taxonomy of Green Algae” took place at the House of Scientific Workers of the Slovak Academy of Sciences in Smolenice-Castle, Czecho-Slovakia, June 25–29, 1990. The meeting was attended by 76 participants from 22 countries of different continents. 26 lectures were given and 30 poster presentations were exhibited. The scientific programme deals with the chlorophytes taxonomy general topics, taxonomy of individual groups of freshwater chlorophytes incl. microworkshops on taxonomy of chlorococcal genera Chlorella and Scenedesmus , respectively, and on the genetics and biochemistry of Chlamydomonas . One half-day excursion was organized during the symposium, and two parallel trips at the end of the symposium.