In order to more specifically define splenic abnormalities with gray-scale ultrasound, a prospective study was performed involving 40 patients with splenomegaly and/or diseases of the spleen. The following sonographic patterns were found: (a) uniform splenic sonodensity, equal to that of the liver (normal); (b) uniform splenic sonodensity, less than that of the liver (low sonodensity); (c) focal defect, more dense than adjacent spleen (sonodense and sonolucent perisplenic defects. Each pattern was found to be associated with certain pathologic categories, which formed a basis for the ultrasonic-pathologic classification of splenic disease. With the use of these patterns, a more specific diagnosis of splenic abnormalities may be made.