Gonadism is a medical term for decreased functional activity of the gonads (ovaries or testes) producing hormones and gametes. Male hypogonadism is characterised by a deficiency in testosterone a hormone critical for sexual, cognitive and body function as well as development. Low testosterone levels can be due to hypothalamic, pituitary or testicular abnormalities. Hypogonadism is classified as primary (primary testicular failure) and secondary (a problem in the hypothalamus or the pituitary gland). Diagnosis requires the presence of symptoms and signs suggestive of testosterone deficiency as well as biochemical evidence. A testosterone level above 12 nmol/l does not require replacement. Patients with testosterone levels below 8 nmol/l will usually benefit from treatment. We present the case of a 58-year-old father of two referred to clinic with a one-year history of erectile dysfunction, reduced libido, absence of morning erections and gynaecomastia. He had a past medical history of hypertension and hypercholesterolaemia. Of note, the patient had been under significant stress relating to the breakdown of his marriage. His blood tests showed vitamin B12 270 ng/l, haemoglobin A1C 41 mmol/mol, serum follicle stimulating hormone 86 IU/l (019), serum luteinising hormones 25.9 IU/l (1.28.6), ferritin 53 μg/l, prolactin 247 mIU/l, serum testosterone 5 nmol/l, normal thyroid function tests/urea and electrolytes/full blood count/liver function tests and prostate specific antigen. On review in clinic, the patient weighed 90 kg with an elevated blood pressure 147/79 mmHg and pulse rate 86 beats per minute (regular). On examination, he had bilateral non-tender gynaecomastia and small volume testes without any palpable masses. An ultrasound (US) testes confirmed small volume testicles (right testicular volume 3 ml, left testicular volume 4 ml) with a hypoechoic avascular lesion in the right testicle measuring 3.9×3.1×3.1 mm. The patient was referred for urology review and repeat scrotal US in 3 months for interval assessment of the lesion. The patient was diagnosed with primary hypogonadism with a plan to initiate testosterone replacement therapy (the primary treatment option). Current guidelines on the management of sexual problems in men advocate pre-treatment assessment to rule out prostate cancer in men over the age of 40 years. Men with erectile dysfunction and/or diminished libido and documented testosterone deficiency are candidates for testosterone therapy once a diagnosis of hypogonadism is confirmed. After the initiation of therapy, total testosterone, sex hormone binding globulin (SHBG) and albumin levels should be monitored. The aim of therapy should be a total testosterone level of at least 15 nmol/l.