This volume presents the proceedings of the International Symposium on Male Sterility for Motility Disorders, held in Paris, on January 30-31, 1998. The internationally recognized faculty present 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.