Serial cranial sections of seven human fetuses between 11 and 18 weeks were studied using Palmgren's silver impregnation technique. The vomeronasal organ revealed receptor cells in four cases. This is the first demonstration of functional elements in the vomeronasal organ in man. They may also be present in old-world monkeys. It is evident that the human vomeronasal organ is frequently present in man, but differentiation of the organ and its individual constituents shows considerable variation.