A preliminary study for establishing sex identity by Mandibular Canine Index is described. Seven hundred and sixty six individuals from a South Indian population of either sex, ranging in age from 15 to 21 years, with fully errupted, healthy and non-worn mandibular permanent canines were studied. The data collected was analysed statistically. Accurancy of sex determination identity was found to be 84.3% in the male and 87.5% in the female. The method is simple and inexpensive to conduct and therefore can be applied in Forensic Odontology, as a method for establishing sex identity.