The basic work-up of patients seeking medical care for erectile dysfunction should include an accurate medical and sexual history, a careful general and andrological physical examination, hormonal evaluation (total testosterone and sex hormone-binding globulin in all men, prolactin and thyroid hormone evaluation in some men) and routine biochemical exams (total and high-density lipoprotein cholesterol, triglycerides, fasting glucose and glycosylated haemoglobin). Second-line evaluation should be limited to those with abnormal first-line results.