Few North American studies have quantified differences in bat community composition between summer and winter. In southerly regions, especially the coastal plain of the Gulf of Mexico, winters are mild and experience only short periods of freezing weather annually. In regions such as this, there may be a substantive community of bats that are active in the winter. We examined seasonality of the bat community in the Kisatchie National Forest of Louisiana. We mist-netted bats for 130 nights during winter and 51 nights during summer and caught 200 and 190 bats, respectively, from 10 different species. Corynorhinus rafinesquii (Rafinesque's Big-eared Bat), Lasiurus borealis (Eastern Red Bat), and Lasionycteris noctivagans (Silver-haired Bat) were more frequently captured in winter, all other species were captured more frequently in summer. Significant differences existed between summer and winter in species richness and abundance of bats, but not for Shannon's diversity index. Across the entire year and in winter, more bats were caught on nights with higher temperature than on nights with lower temperatures. Although there was much temporal variation in species composition, we found a substantial bat community that is active in the winter in the Kisatchie National Forest of Louisiana.