Many women have to spend one third of their lives in a postmenopausal state and they should have a good quality of life during this period. Althoug HRT is well accepted as the logical treatment of climacteric problems, the prevalence rate is very low in some countries. The reasons for not accepting HRT are manifold and complex. The objective of this book is to describe the essential advances in basic and clinical research that forms the basis of current HRT and to give an overview of the efficacy and safety of HRT.