A patient experienced sudden relief from the splenomegaly and other signs and symptoms of lymphatic leukemia and has remained free from all manifestations of the disease for more than five years. The onset occurred with rapid loss of weight in August, 1951, when the patient was 52 years old. Physical findings, hematological data, and results of lymph node biopsy were typical of chronic lymphatic leukemia. Treatment included repeated transfusions of whole blood, roentgenotherapy applied to the much enlarged spleen, and injections of liver extract. For two years the patient did not improve except temporarily after transfusions. The splenomegaly subsided abruptly in August, 1953, and when the patient was reexamined in September, 1953, her weight, appearance, blood cell count, and bone marrow were normal. They have remained so.