A comparison has been undertaken between conventional radiographic imaging and computed tomography (CT) in 35 patients with testicular teratoma as part of an audit of our investigative approach to staging and follow-up. The CT examination included alternate cuts from the carina of the trachea to the lung bases as the thoracic assessment as well as the standard examination of the abdomen. Lymphangiography appeared to detect Stage IIa lesions better than did CT; however, CT was able to define the volume of abdominal disease more accurately. During the follow-up of Stage I patients, CT detected progressive disease in the absence of tumour marker elevation. Such progressive disease presented within 4 months in the majority of cases. The selective thoracic CT scanning conferred no advantage over whole-lung tomography, only one additional lesion being detected in 123 examinations. It is recommended that CT should be reserved for examining the area above the renal hila, for cases where lymphangiography is equivocal or positive, and that CT scanning of the abdomen in Stage I patients not receiving therapy should be repeated every 3 months following orchidectomy for the first year, irrespective of clinical status.