The Vallanadu Blackbuck Sanctuary (VBS), Tamil Nadu, India is a small protected area (PA) designated to conserve blackbuck. We did a study on habitat use and suitability in the PA that has come under various management interventions. The occupancy of blackbuck was positively correlated with areas lying within the PA, but the encounter rate of blackbuck was significantly higher in areas outside the PA. Being small in size, VBS may not hold a large population of blackbucks, but may help in saving the species which once widely occurred in the southernmost parts of India.