A study of nasal biopsies from 137 leprosy patients classified on the basis of clinical, microbiological and skin biopsy as Indeterminate, Tuberculoid, Borderline-tuberculoid and Borderline-leproma was undertaken. Changes suggestive of leprosy viz., nerve and smooth muscle inflammation with a few acid fast bacilli in a proportion of the biopsies were seen in all groups of patients examined. This suggests, that even in Indeterminate and Tuberculoid leprosy the disease becomes generalised by the time clinical manifestations appear in skin. Tuberculoid granuloma was seen in two nasal biopsies from Borderline-tuberculoid leprosy patients, one of which was located in the wall of a vein, suggesting the possibility of intravascular dissemination of the disease even in non-lepromatous leprosy. 33 of the patients were children 15 years and below and they also showed changes such as nerve and smooth muscle inflammation but bacilli were seen only in the Borderline group. These findings suggest involvement of the nasal mucosa early in the course of the disease as 70% of the children had the skin lesion for less than one year. The nasal mucosa offers favourable conditions for the growth of the organisms and is readily accessible to infection by droplets, and therefore, it could be one of the primary sites of involvement in leprosy.