One hundred and twelve subjects including 82 patients with diffuse hepatic diseases were examined by clinico-biochemical and instrumental methods. The latter methods included liver scintigraphy and radionuclide study with technetium-99M-colloid, ultrasonic exploration of the liver and spleen, and computer-aided tomography. According to the changes in the clinical and biochemical symptomatology and to the instrumental diagnosis data all the patients were divided into several groups. The first group comprised 30 subjects with fatty liver dystrophy (FD). In these patients, ultrasonic examination revealed two types of changes depending on the disease duration and severity. Seven patients had associated hepatitis and FD of the liver. In patients with active hepatitis (15 cases) and persistent hepatis (17 cases), scintigraphy revealed liver enlargement twice as often. In patients with liver cirrhosis, ultrasonic diagnosis was helpful in revealing differences at the initial and advanced stages of disease. Scintigraphy appeared to be the most sensitive method, whereas computer-aided tomography the least sensitive. Computer-aided tomography and ultrasonography proved to be the most specific.