Analysis of 17 cases of coexistent sarcoidosis and malignant lymphoproliferative disease, supplemented with 29 similar cases reported in the literature indicates that this association is not fortuitous. In addition, significantly more malignancies other than lymphoma were found in this group of patients. A sarcoidosis-lymphoma syndrome appears to exist in which malignant lympho-proliferative disease develops at least 5.5 times more often than expected in middle-aged patients with chronic active sarcoidosis, possibly as a consequence of the immunologic abnormalities observed in the latter disease.