Aim: To study the morphological characteristics of dorsal guard hair of five carnivoran species native to Tamil Nadu for the creation of an identification key for application in wildlife forensics. Study Design: The experiment was designed to observe the physical characters of each hair strand and measure widely used morphological parameters from native species of the state. The results were compared with previous findings to validate the differences and similarities with our study. Place and Duration of Study: Advanced Institute for Wildlife Conservation (AIWC), Tamil Nadu Forest Department, Vandalur, Chennai, Tamil Nadu, between August 2020 and September 2021. Methodology: Hair samples were collected for golden jackal, Indian fox, dhole, sloth bear and Indian grey mongoose. Hair characters such as scale pattern, scale distance and scale margin, medulla structure, cortex thickness, medulla thickness, medullary index and cross-sectional structure were observed. Results: The hair length of golden jackal, Indian fox, dhole, sloth bear and Indian grey mongoose were as follows 44.94 ± 2.24 mm, 29.70 ± 1.51 mm, 29.60 ± 0.97 mm, 83.83 ± 2.93 mm, 54.60 ± 2.03. The cuticular characters showed few variations compared to previous studies. The medullary structure was wide medulla with vacuoles for all three canid species while sloth bear has a narrow simple unbroken medulla and Indian grey mongoose had wide medulla with lattice. The medullary index for golden jackal, Indian fox, dhole, sloth bear and Indian grey mongoose were 0.73 ± 0.05 (S.D.), 0.77 ± 0.071 (S.D.), 0.66 ± 0.06 (S.D.), 0.18 ± 0.08 (S.D.) and 0.63 ± 0.05 (S.D.) respectively. Conclusion: The morphometric characters of hair showed variation in scale pattern, scale margin, scale distance and medullary index when compared to the previous studies. The research was successful in creating a taxonomic key for identifying the five mammalian species from their guard hair.