BACKGROUND: There is limited information available regarding the relationship between clinical indicators of widespread disease in patients with lung cancer and the findings of transcutaneous ultrasonography. METHODS: A retrospective survey was made of 279 consecutive patients with lung cancer. By reviewing the patients' records the clinical findings were divided into symptoms, signs, and laboratory tests indicative of metastatic disease. All patients had been examined by abdominal ultrasonography. RESULTS: The patients included 19% with small cell carcinoma. The frequency of abdominal metastases by ultrasonography in those with small cell carcinoma was 40%, in the other patients it was 8%. Regardless of histological group, all the 40 patients with abdominal metastases by ultrasonography had at least one clinical category indicative of widespread disease and 38 (95%) had two or all three clinical categories positive. Fifty nine patients had no clinical indicators of metastases and none of these had abdominal metastases by ultrasonography. CONCLUSIONS: The results of this study indicate that abdominal metastases are found in lung cancer patients with clinical findings indicative of widespread disease. No abdominal metastases were found in patients with a negative clinical evaluation. The results indicate that transcutaneous ultrasonography of the abdomen is not necessary in the initial staging if the clinical evaluation is unremarkable.