Between January 1981 and December 1989, a total of 205 patients with lung cancer were treated in different multicenter trials in our hospital. In 130 cases, small cell lung cancer (SCLC), and in 75 cases, non-small cell lung cancer (NSCLC) was diagnosed. Abdominal sonography for pretreatment staging revealed liver metastasis in 59 patients (42 SCLC, 17 NSCLC), sonographic patterns of liver metastasis were described and the prognostic significance of evaluation of response according to abdominal ultrasound after the first two cycles of treatment was investigated. For both histological types of lung cancer, the hypoechoic or isoechoic (80%), small noduled (97%) liver metastasis with multifocal spread (86%) was found to be typical. Sonographic follow-up examinations for liver metastasis were performed in 46 patients (35 SCLC, 11 NSCLC), and 134 chemotherapy cycles. Response to chemotherapy according to abdominal ultrasound was seen in only 3 out of 11 patients with NSCLC (27%) and 17 out of 35 with SCLC (49%). Best response was achieved after the first two cycles with only 6 patients (6 SCLC, 0 NSCLC) exhibiting complete liver metastasis remission. All other patients exhibited on ultrasound a progressive or non-responsive illness. In summary, sonography is reliable with respect to the diagnosis and follow-up examination of liver metastases in lung cancer. A lack of metastasis regression subsequent to the first two cycles of therapy is associated with poor prognosis and continued treatment cannot be justified in such patients.