The fertilizing ability of human spermatozoa depends upon numerous functions such as motility, normal morphology, ability to bind to the zona pellucida and to undergo the acrosome reaction. Hence a lot of tests have been developed to try and predict IVF results. In a previous study we had established a scoring method, based on parameters such as sperm morphology, vitality, motility and the acrosome reaction, which was able to predict up to 83% of in-vitro fertilization results. The present study aimed to validate this score on a separate set of sperm samples. The results confirmed those of the first series. The score allowed prediction of fertilization failures with a 56% sensitivity, a 91% specificity, a 56% positive predictive value and a 91% negative predictive value. Therefore, this score could be used routinely to choose between conventional IVF and ICSI.