Purpose: To determine in a couple where the male had globozoospermia with failed fertilization despite intracytoplasmic sperm injection (ICSI) if fertilization could be achieved by using high magnification ICSI or by oocyte activation by calcium ionophore Methods: Twenty eggs were retrieved and divided according to source of sperm, i.e., ejaculated by testicular aspiration or with donor sperm. Following ICSI the eggs were exposed to calcium inophore within one hour. The sperm were magnified 6300x in an attempt to find some sperm with evidence of at least some acrosome Results: None of the seven eggs inseminated by ICSI with ejaculated sperm or the seven inseminated with JCS! with testicular sperm fertilized even with attempted oocyte activation with calcium ionophore. However, four of the six oocytes that were inseminated with donor sperm did fertilize. None of the round-headed sperm showed any partial acrosome even using high magnification ICSI Conclusions: It is possible that for successful fertilization with round-headed sperm there has to be at least enough acrosomal material to make some sperm-associated oocyte activating factor.