We investigated the diet of Corynorhinus rafinesquii (Rafinesque's Big-eared Bat) in west-central Louisiana by examining fecal pellets collected from beneath 3 bridges used by these bats as day roosts. Fresh fecal material was found under the bridges during every month of the year. We detected 5 insect orders, including 5 families, in fecal pellets collected from 25 August 2005 to 5 January 2007. Lepidoptera represented 93.7% of the total volume and was the only order observed in 100% of our samples. Coleopterans, mostly Scarabaeidae, were the second most abundant food item and represented 5.8% of the total volume. Hemiptera, Diptera, and Hymenoptera together represented 0.4 % of the total volume. We observed Diptera, Hemiptera, Hymenoptera, and Coleoptera in fecal pellets collected under some, but not all bridges. No insect orders were observed that had not previously been reported as prey of Rafinesque's Big-eared Bats. Our results were similar to those reported in studies conducted in Kentucky, North Carolina, and Florida, and we concluded that Rafinesque's Big-eared Bats primarily prey upon lepidopterans in Louisiana.