The relationship between spermatozoan volume and sperm head morphometry in human semen was examined. The study group consisted of 28 males attending an in-vitro fertilization program. Semen samples were obtained by masturbation after at least 3 days of sexual abstinence and assayed for semen volume, sperm concentration, sperm morphometry, and motility. Morphometry scores were constructed from measures of sperm head perimeter, area, length, and width. Fertility was assessed in an in-vitro procedure using preovulating oocytes. Semen samples from 22 subjects were considered to be fertile. Mean sperm concentrations, motility, and morphometry scores were lower in samples from the six subjects judged to be nonfertile than in the fertile samples, but the differences were not statistically significant. Semen volumes were similar in both groups and were poorly correlated with the morphometry scores. The correlation coefficients between the morphometric parameters and volume were positive in the fertile samples and negative in the nonfertile samples except for width versus volume. The authors conclude that semen volume and semen quality as measured by various sperm cell morphometric parameters may be correlated with fertility.