The computed tomography (CT) findings in three patients with invasive pleural mesothelioma are presented, and the invasive route and metastatic extension of the disease in the abdomen and retroperitoneum are discussed. These findings indicate the value of CT in detecting the extrathoracic extension of mesothelioma. Abdominal CT studies should be obtained in evaluating mesothelioma patients for extrathoracic extension of the disease. © 1983.