A phenotypic female presented initially at the age of 17 years with amenorrhoea and delay of sexual development. Karyotype was male, 46 XY, and as gonads were absent, a diagnosis of congenital anorchia was made. The patient was treated with oestrogen. At the age of 23 years, she re-presented with tall stature and hypertension. She then had normal female habitus but absent pubic and axillary hair. Re-investigation showed that sex steroids and cortisol were absent and established the diagnosis as 17 alpha-hydroxylase deficiency. Treatment with hydrocortisone rapidly corrected the hypertension. Ultrasound examination confirmed the absence of gonads but showed that a small uterus was present. Measurement of serum cortisol is important for recognition of such patients, but further measurements of sex steroids, particularly progesterone, are needed to prove the diagnosis. We have found no previous reports of absent gonads in 17 alpha-hydroxylase deficiency. The association remains unexplained.