Phospholipase B from Schizosaccharomyces pombe was purified by ammonium sulfate fractionation and chromatographed on phenyl-Sepharose CL-4B, DEAE-Toyopearl 650M, and TSK gel G4000SW columns. The purified enzyme was a glycoprotein with molecular weight of approximately 300,000 and 100,000-150,000 by gel filtration and SDS-polyacrylamide gel electrophoresis, respectively. The isoelectric point was pH 4.7. The optimum pH of the enzyme was 2.5 and no activity was detected at neutral and alkaline pHs. The enzyme was not heat-stable. Enzyme activity was slightly stimulated by divalent ions except Fe2+ and 0.1% sodium deoxycholate, and inhibited by Fe2+, Fe3+, 0.1% sodium dodecyl sulfate, and 0.01% cetyltrimethylammonium bromide. The enzyme hydrolyzed mono- and diacylphospholipids, and phosphatidylinositol was hydrolyzed most preferentially. Triglyceride was not hydrolyzed. The enzyme also had acyltransferase activity on lysophosphatidylcholine, forming the corresponding diacylphosphatidylcholine.