A case of digitoxin-induced thrombocytopenia is reported in a 76-year-old female patient who had been treated with digitoxin over a period of 5 years. This thrombocytopenia was associated with a moderate eosinophilia and clinical signs of severe digitalis intoxication. A search for thromboagglutinins and the culture of lymphocytes provided significantly positive results, establishing consequently the digitoxin’s responsibility. Further evidence is provided by the fact that the discontinuation of digitoxin was followed by a slow return to normal of the platelet count. The administration of digoxin, on the other hand, was perfectly tolerated.