This book is a summary of the present state of the art in the physiology of both endometrial receptivity and implantation. Although these physiological processes are today considered as limiting factors responsible for both infertility and low gestation rates in patients undergoing assisted reproductive techniques, they may, on the other hand, represent future targets for contraception. Several aspects of endometrial receptivity and implantation are discussed in this book. In the first part, basic aspects of the cell biology of endometrial functions as well as the molecular aspects of endometrial receptivity and implantation are discussed. Subsequently the clinical and experimental approaches to endometrial contraception are considered. Finally, some basic questions are raised pointing to the need for further research in order to gain a better understanding of the implantation process and the development of new contraceptive strategies, including the inhibition of endometrial receptivity. The organizers of the workshop and the editors of the volume hope that this book will encourage both universities and the pharmaceutical industry to initiate and/or continue research on endometrial receptivity and implantation.