Activation of coagulation and fibrinolysis occur in exercise. Available evidence suggests that strenuous exercise induce activation of blood coagulation with concomitant enhancement of blood fibrinolysis men, women and adolescents. Although the responses of blood coagulation and fibrinolysis appear to be related to the exercise intensity and duration, recent reports suggests that moderate exercise intensity is followed by activation of blood fibrinolysis without simultaneous hyper-coagulability, while very intense exercise is associated with concurrent activation of blood coagulation and fibrinolysis. Exercise effects on platelet aggregation and function in healthy individuals have produced conflicting results. However for patients with history of coronary heart disease, the preponderance of available evidence would suggest that platelet aggregation and functions are increased with exercise. Meagre information exists on the effect of exercise training on blood coagulation and fibrinolysis and the exact effects are not as yet known. Recent reports suggest that training-associated improvement in markers of endogenous fibrinolysis appear to be related to the intensity and duration of the training programme. Although the effects of physical training on platelets have been briefly investigated, the evidence reported recently suggests that exercise training is linked with favourable effects on platelet aggregation and activation in both men and women.