Eighteen men presenting with metastatic germ-cell malignancy in whom no primary tumour could be palpated in either testis are described. All patients had both testes in the scrotal sac and none had a history of maldescent. All had abdominal node involvement, in most cases associated with metastases at other sites. Ten men presented with Stage 4 disease, five with Stage 3 and three with Stage 2. The most common histological sub-type associated with an occult primary testicular tumour was trophoblastic malignant teratoma (9/18 patients). Abdominal pain (12 patients) and systemic symptoms (10 patients) were common presenting features. There was a history of testicular atrophy in eight patients and seven had experienced episodes of transient testicular pain up to 18 months before presentation. In three of four patients in whom the testis was examined histologically following a history of atrophy and/or pain, there was evidence of a primary tumour, manifest as spontaneous tumour regression (one), differentiation (one) or a small micro-primary trophoblastic teratoma (one). In a fifth patient an ultrasonic scan showed a 1-cm echogenic mass in an atrophic testis. In 10 patients the diagnosis of germ-cell malignancy was established by laparotomy. Obstructive uropathy was present in six patients, associated with haematuria in four patients.