Andrology is the name given to that part of urology which relates to disorders and diseases of the male genital tract. Initially, it was mainly related to the management of male infertility. With the development of infertility clinics, normally run by gynaecologists, that aspect of the male genital tract represents a decreasing part of urological practice. In its place, however, has come a now rapidly developing interest in the management of male sexual dysfunction. The assessment of disorders of erection and ejaculation has involved the establishment of specialised clinics, supervised by urologists with an interest in this problem. This interest relates not only to those patients presenting with psychological and medical disorders causing erectile dysfunction, but also the increasing number of patients who, as a result of major pelvic surgery in the treatment of cancer, both surgical and urological, have acquired erectile dysfunction through the unavoidable occurrence of nerve damage during those major operative procedures.