Processes essential to reproduction known to occur in the oviducts of Eutherian mammals include sperm transport, capacitation, ovum pick-up and transport, fertilization and embryo transport and nourishment. Our knowledge of these processes in our own species, man, is incomplete. The reasons underlying our lack of information concerning the physiology of the human Fallopian tube are ethical, philosophical, and technical. Although some of our failure to obtain definitive data in women has been due to ethical constraints we have also been limited philosophically by our inability to formulate the critical questions, and pragmatically by the lack of technology with which to accurately measure many biological phenomena. After more than a half century of clinical interest in female infertility, we are unable to assess accurately a single physiological function of the Fallopian tube. Our clinical armamentarium is limited to appraisals of the patency of the tube to gas or liquid, and to examination of the external appearance and texture of the tube. Even if all ethical constraints were removed, it would still be necessary to identify the important questions, design the critical experiments, and to develop the required technology.In this essay we shall emphasize postovulatory events, specifically fertilization, ovum pick¬ up, and ovum and embryo transport. We will discuss the pertinent physiological phenomena, and then we shall attempt to correlate tubai anatomy and physiology with clinical considerations.