Abstract
Animal experiments have suggested that vasectomy may disturb the endocrine function of the testis. To explore this possibility in man blood was obtained from 277 men who had undergone vasectomy up to six years earlier or who were about to undergo the operation. Mean plasma testosterone concentrations seemed to be slightly higher in those who had undergone vasectomy than in the preoperative group, although this difference was not statistically significant. There was no significant difference between these two groups in the concentrations of luteinising hormone, follicle-stimulating hormone, prolactin, or oestradiol.