We have observed a secreting tumor of the testis classified as an intermediate malignant teratoma type A. This hormone secreting tumor was associated to bilateral gynecomasty. Surgery with radiotherapy were followed by disappearance of all symptoms for two years. Hormone levels, that were abnormal, returned to normal. Next to seminomas, testis teratomas are grouped in different types according to their differentiation, from well organized tissues to totally anaplastic cells. Clinical manifestations of these lesions are essentially dependent on their secretory capacity. Gynecomasty secondary to oestrogenic production of chorionic gonadotrophins or pituitary hormones, is the usual symptom; one may encounter hyperthyroidism or hypercortisolism. Generally, resection of the tumor is followed by a return to normal hormone values; recurrence of pathological values is often a sign of metastatic evolution. The treatment is orchidectomy with radiotherapy or eventually with chemotherapy.