This volume is the proceedings of the International Symposium on Male Sterility for Motility Disorders, held in Paris, January 30-31, 1998. The internationally recognized faculty present the latest research on etiologic factors and treatment of male sterility for motility disorders, including the etiology of immobile sperm; therapeutic possibilities for immotile sperm; ICSI option; testicular sperm, physiological and pathological aspects and retrieval; and conceptus quality in ICSI and ethical problems with ART.