We analyzed fecal pellets from 59 Nyctinomops femorosaccus and 54 Tadarida brasiliensis to assess dietary overlap in an area of sympatry. Lepidoptera, Hemiptera, and Coleoptera were the most abundant orders of insects. Niche-breadth indices were narrow overall and highest in June for both species. Indices of overlap indicated nearly complete overlap in use of resources. There does not appear to be resource partitioning of diet at the taxonomic level examined in these species during summer when sources of food are expected to be more abundant. There was a dietary shift from predominantly Lepidoptera to Hemiptera in March for N. femorosaccus, but not for T. brasiliensis. Resources other than food may impose a greater limitation on size of these populations.