Tumours of the prostate are the commonest types of neoplasm in the male. Whilst the benign form is virtually a universal condition in the ageing male, malignant tumours rank amongst the top causes of cancer death. Despite the fact that the involvement of the testis in the growth of the prostate has been recognised for almost two centuries, it was not until the early 1940s that Charles Huggins' studies on the effect of orchidectomy and oestrogen therapy on prostatic cancer initiated endocrine manipulation in the management of this malignancy. During the 1960s progress in the understanding of the mechanism of hormone action, achieved through advances in molecular biology and the recognition of certain aspects of hormonal control in relation to the genome, introduced a new dimension for approaching endocrine manipulation of prostatic tumours. By the end of that decade a new scientific discipline devoted to prostate research had been born, which brought together investigators in the fields of molecular biology, biochemistry, endocrinology, immunology, urology and pathology to search for the cause and to explore methods for advancing the management of abnormal prostatic growth. Since then a wealth of scientific data has accumulated on the prostate in which endocrinology has manifested itself as the cardinal aspect to which most of the findings can be related.