Non-invasive tests such as ultrasonography (US) and serum CA 19-9 or CA 50 present substantial sensitivity, but are not devoid of false-negative results in the diagnosis of pancreatic cancer. The patient sample in this study comprised 58 patients, 51 with adenocarcinoma, 4 with cystadenocarcinoma, 2 with islet-cell carcinoma and 1 with anaplastic carcinoma. All the patients underwent US examination with evaluation of visible tumour volume by means of the sphere or ellipsoid rotation formula. Serum CA 19-9 was measured in all cases, and CA 50 in 50. Pancreatic tumours were diagnosed by US in 47/58 patients [sensitivity (S) = 81.03%] and ductal carcinomas in 46/55 (S = 83.6%). Abnormal CA 19-9 values were found in 48/58 subjects (S = 82.7%) and in 47/55 ductal carcinomas (S = 85.4%). CA 50 showed abnormal values in 39 of the 50 tumours assessed (S = 78%) and in 38/47 ductal carcinomas (S = 80.8%). Combined use of the tests considerably improves these sensitivities. It is concluded that US results can be improved when combined with the two antigen assays. The poor correlation between tumour mass and serum antigen levels is compensated for by the US performance. The combination of US plus CA 19-9 and CA 50 provides a very good tool for the rapid non-invasive diagnosis of pancreatic cancer.