The vomeronasal organ (VNO) was studied in ten human foetuses, 12 to 36 weeks old. At 12 to 23 weeks, it was lined by a smooth pseudostratified epithelium, with neurone-specific enolase (NSE) positive cells looking like olfactory receptors. Clusters of NSE-positive cells were seen in relation with the posterosuperior end of the organ and along nerve fascicles in the nasal septum. At 36 weeks, the organ was lined by a respiratory epithelium and did not show any receptor-like cells; some pear-shaped NSE-positive cells of unknown significance were seen at the upper part of the respiratory epithelium. Our results suggest that during the early foetal period, the VNO could have some, as yet unknown, sensory function.