Small mammal communities were studied in four tropical habitats (dry thorn, dry and moist deciduous, and semi-evergreen forests) in Mudumalai Wildlife Sanctuary, southern India. Species composition, community structure, and population variables of small mammals in these habitats were examined. The relationship between small mammal community structure and select habitat variables was also examined. Six species of rodents and one insectivore were represented by 396 captures of 195 individuals out of a total of 7,425 trap nights (5.3% capture rate). Small mammals showed distinct distribution patterns across habitat types. Community structure, species richness, species diversity, relative abundance, and biomass varied across habitats, with each type having a different dominant species. Cremnomys blanfordi, which was the most abundant species, comprised 39%, Mus platythrix 29%, Rattus rattus 12%, M. musculus 9%, Tatera indica 5%, Suncus montanus 5%, and Platacanthomys lasiurus 1% of captures. Deciduous forest habitats supported the highest abundance and biomass of small mammals. However, based on the distinct distribution patterns, all four forest types are believed to be important for maintaining the local diversity of small mammal populations. Small mammal abundance was positively correlated with habitat heterogeneity. Although the community structure of small mammals is broadly determined by habitat structure, the specific microhabitat preferences of individual species could not be determined from these data.