We report the case of a 52 year old gentleman who presented to Primary Care with a short history of gynaecomastia, loss of libido and erectile dysfunction. He was normally fit and well, with no past medical history and no regular medications. Initial blood tests showed low testosterone (0.7 nmol/l (normal 1128)) with inappropriately low gonadotrophins (LH 1.2iU/l (1.59.3), FSH <0.1 iU/l (1.418.1)). Other blood tests were unremarkable (TFTs, prolactin, FBC and U&Es). A diagnosis of hypogonadotrophic hypogonadism was made. However, in view of gynaecomastia, an oestradiol level was added on later. This was significantly elevated at 932 pmol/l (28156). Following these results, the gentleman was referred to Endocrinology. Repeat bloods confirmed both hypogonadotrophic hypogonadism and hyperoestrogenaemia. MRI of the adrenal glands demonstrated a right sided well-circumscribed supra-renal mass measuring 8 cm x 8 cm. CT scan excluded distant metastases. Other blood tests revealed normal plasma metanephrines, aldosterone, plasma renin activity, cortisol, gut hormones, overnight dexamethasone suppression test, DHEAS, androstenedione and 17OH-progesterone. The MDT determined this gentleman was likely to have an oestrogen-secreting adrenal tumour and he underwent right open adrenalectomy. Post-operatively, the gynaecomastia resolved and he noted rapidly improved libido and energy levels. Four weeks after surgery, bloods demonstrated normalisation of the oestradiol (151 pmol/l) (<150) and testosterone (19 nmol/l (830)). Histology demonstrated adrenal cortical carcinoma (ACC) pT3Nx Ki-67 60%. There were also tumour cells present at the margins, thus adjuvant chemotherapy with mitotane was initiated. ACC is rare, with an annual incidence of 12 per 1 million. Specifically, feminising adrenal tumours such as in this case, account for less than 2% of all cases. Typical presenting features are demonstrated here with gynaecomastia, loss of libido and erectile dysfunction. Additionally, this case demonstrates the importance of checking oestradiol levels in cases of hypogonadotrophic hypogonadism where the cause is unclear.