CONTEXT Assessment of sex has significant contribution in construction of a physical profile of the decedent along with other parameters like race, stature and age. Sex determination with aid of skeletal remains is difficult procedure when, only a part of the body is obtainable. To solve this difficulty, tooth size standards based on odontometric data can be used in age and sex determination. The present study was undertaken with the objective to evaluate the reliability of sex determination using discriminant canine index (DCI). METHODS A total of 120 subjects, with healthy periodontium and between the age groups of 15 to 40 years were selected randomly. Subjects with hard tissue abnormalities were excluded from the study. The maximum mesiodistal widths of left mandibular canines were measured intraorally with the help of divider and digital vernier caliper. Data was collected and analyzed statistically. RESULTS A significant increase in the mesiodistal width of canines in males (7.21 ± 0.45 mm) when compared to females (6.77 ± 0.29 mm) was observed. The discriminant canine index (DCI) has identified 68.3% of males and 76.7% of females correctly with an overall accuracy rate of 72.5%. CONCLUSION The present study indicated that the DCI can produce reliable results and can be used as an alternative for mandibular canine index (MCI), for sex determination.