The bivalve family Sphaeriidae of Poland is revised. The paper contains descriptions and drawings of all 21 species of the recent fauna of Poland (3 species of the genus Sphaerium Scop., 1 of Musculium Link and 17 of Pisidium Pfeiff.). Description of particular species includes the data concerning shell morphology and its variability, ecology and distribution. A key to Polish species of Sphaeriidae is also given.