The split ejaculate has proven to be a reliable method for concentrating sperm in a small volume. However, there is some controversy whether the spermatozoa in the most sperm-rich fraction of the split ejaculate has better motility than the spermatozoa in whole semen. In this study, at least two specimens of whole semen and two split ejaculates were obtained from 45 infertile males. The mean values for the parameters of the semen analysis were compared statistically. Our data indicate that increased sperm density is a consistent finding with the split ejaculate, even for severely oligospermic men. However, improved sperm motility with the split ejaculate is more variable. On the other hand, patients with mild oligospermia (10 to 40 million sperm/ml of whole semen) and high semen volumes (greater than 5.0 ml) demonstrated improvement in all parameters in the split ejaculate.