Urinary 17-oxosteroid values in excess of 100 mg./24 hr. are not uncommonly associated with virilizing tumours of adrenal origin. However, the secretion of pregnanetriol in amounts greater than 50 mg./24 hr. is unusual. The patient reported here exhibited the highest level of pregnanetriol excretion due to adrenal tumour without metastases ever recorded in the English literature. A 47-year-old Negro woman presented with a 10-month history of hirsutism, darkening of the facial skin, periorbital oedema, abdominal swelling, and right flank pain, progressively severe and debilitating. Twenty years previously, total abdominal hysterectomy and bilateral salpingo-oophorectomy had been accomplished for pelvic inflammatory disease. Physical examination revealed a round-faced hirsute Negress in no distress with blood pressure of 150/105 mm. Hg, atrophic breasts, masculine abdominal and pubic hair distribution and patchy hyperpigmentation of the face and arms. The liver was palpable 4 cm. below the right costal margin and was only slightly tender. The