The purpose of this chapter is to examine, in postmenopausal women, the effect of physical activity (PA) on overall mortality, cardiovascular mortality and prevention of cardiovascular disease, bone health and body composition. An analysis of the scientific literature was carried out and more than 100 studies were selected. In postmenopausal women, regular endurance PA significantly reduced overall and cardiovascular mortality. It is effective in primary and tertiary prevention. Regarding bone health, combined exercises combining weight-bearing exercises with impacts associated with muscle strengthening are the most effective to maintain or improve bone mineral density and prevent fractures. In terms of body composition, regular endurance or combined PA (endurance+muscle strengthening) decreases visceral fat regardless of BMI, and this in the absence of caloric restriction. For muscle mass, only muscle strengthening or combined training (endurance+muscle strengthening) have shown their effectiveness in slowing down the loss of muscle mass or even in increasing it. In all cases, the minimum duration of PA is 12 weeks and above all, it must be continued so that the effects are maintained over the long term. All these parameters will also be improved with a reduction in time spent sitting, regardless of the level of PA. No study has reported a major incident related to the practice of moderate to high intensity levels of PA, provided that certain precautions are observed, the main one being with regard to cardiovascular risk. The recommendations for postmenopausal women are a reduction in sedentary behaviour associated with specific recommendations for regular physical activity.