This review lecture is primarily concerned with the study of assisted human conception and especially in-vitro fertilization (IVF). It also places in perspective the role of endocrinology in history of IVF. A knowledge of the hypothalamic-pituitary control of ovulation, and of ovarian follicle dynamics is assumed. A detailed consideration of these topics, together with extensive references, are available in a recent textbook (Edwards and Brody, 1995). Many of the early pioneers studying animal reproduction combined reproductive physiology and endocrinology, especially Marshall, who analysed oestrous and menstrual cycles in many mammalian species. The clarification of the roles of pituitary gland and hypothalamus in the menstrual cycle and ovulation, and their regulation by steroidal feedbacks from the gonads gave an immense stimulus to studies on human reproduction (Smith and Engle, 1927; Lewis and Gregory, 1933; Harris, 1970). Three periods of research into assisted human conception are covered in this lecture including the initial work on the introduction of the endocrinology and embryology of human IVF, the rapid advances in technique as it expanded worldwide, and finally some of the recent remarkable advances in the field.