Three patients presenting in a one-year period with coexisting carcinoma and presumed immune thrombocytopenia are the subject of this report. Review of the literature disclosed a paucity of previous reports of this association. Possible pathogenic mechanisms resulting in this association are discussed. All three patients responded to corticosteroids in usual doses used in treatment of chronic idiopathic thrombocytopenic purpura. The association of carcinoma with immune thrombocytopenia may be more common than has been previously appreciated.