One case of digitoxin-induced thrombopenia with relapse upon reexposure is reported. Cytopenia was each time rapidly reversible upon withdrawal of the medication. During the two episodes, blood digitoxin was superior to the generally accepted value. No thrombopenia was caused by administration of digoxin. The criteria for diagnosis and the difficulty of causal demonstration are discussed. Up to the present the literature has reported 11 cases of cardiotonic-induced thrombopenia. The features of these observations are reviewed.