Several authors found that the presence of large vacuoles in the sperm head correlates with several nuclear alterations: DNA fragmentation , abnormal chromatin condensation and aneuploidy . However, these studies are controversial and were performed on few spermatozoa. In order to improve the selection of spermatozoa with a normal chromosomal content, it is essential not only to confirm the existence of a relationship between sperm head vacuoles and altered sperm nuclear quality but also to better characterize these alterations.