1. The clinical, hematologic and post mortem findings in a case of splenic agenesis have been presented. Because of its association with cyanotic congenital heart disease and situs inversus of the abdominal viscera, the anomaly was suspected prior to death. The presence of hematologic abnormalities similar to those found after splenectomy supported this impression. These abnormalities were: target cells, decreased osmotic fragility, Howell-Jolly bodies, transient normoblastemia, siderocytosis, and leukocytosis. 2. The blood picture in splenic agenesis is sufficiently specific to permit the antemortem diagnosis to be suspected even in the absence of severe associated anomalies.