The sonographic patterns of focal lesions of the liver and spleen in 26 patients with Hodgkin's disease and non-Hodgkin's lymphoma are described. Thirteen out of 19 hepatic lesions and nine out of 11 splenic lesions corresponded to a nodular lymphomatous involvement. The remaining cases involved benign focal lesions of the liver and spleen. The vast majority of the hepatic and splenic lymphomatous nodules had a hypoechoic pattern with indistinct edges. Target lesions of the liver were seen only in non-Hodgkin's lymphoma. Echogenic lymphomatous nodules could not be detected. All echogenic lesions (three) were biopsied and found to be benign. Whereas a focal liver involvement almost always occurred in combination with hepatomegaly, only two out of nine patients with splenic foci had splenomegaly. The response of hepatic and splenic lymphoma to chemotherapy is described from follow-up examinations in 11 cases. Because of the inherent risk of over-treatment of the false positive interpretation of hepatic nodules, the large-scale use of needle biopsy in sonographically equivocal lesions is strongly advocated.