The effect of exhaustive running exercise on the phagocytic function of blood polymorphonuclear neutrophils in sedentary young men and women has been studied. Adherence capacity to the endothelium, spontaneous mobility, chemotaxis and ingestion of Candida albicans were not modified after physical exercise. However, opsonization of Candida albicans as well as candidicide power increased significantly in men and women after exercise. The immediate advantages of physical exercise on the phagocytic immune response is discussed.