The hematological findings of 233 patients with brucellosis are presented and the possible pathologies discussed. Anemia was present in 128 patients (55%), leukopenia in 49 (21%) and thrombocytopenia in 59 (26%). Bone marrow aspirates of 18 patients (8%) with pancytopenia were examined. The bone marrow was hypercellular in 15 and normocellular in 3 patients. Granulomatous lesions were detected in 12 cases (67%), and slight to moderate cytophagocytosis of erythrocytes, granulocytes and platelets existed in all patients. Blood cell counts reverted to normal within 2-3 weeks of initiating chemotherapy with recovery from the disease.