Five patients who received cyanidanol for 4-36 months are presented. Three developed both hemolytic anemia and thrombocytopenia, while 2 had only thrombocytopenia. After suspending the drug the hematological values returned to normal in all of the patients. Drug-dependent platelet antibodies were detected in 4 of the 5 patients and cyanidanol-dependent red blood cell antibodies were present in 3. There are various mechanisms involved in the cyanidanol-induced immune cytopenias and, as in the present study, were sometimes simultaneously observed in the same patient.