The shaggy sac-winged bat, Centronycteris centralis, occurs mainly in lowland forests from Veracruz, Mexico, to Peru, although it has been reported from elevations as high at 1450 m in Panama. Most captures of the species are of single individuals, and throughout its distribution, this bat is rare and poorly-known. Centronycteris centralis generally has been assumed to be an aerial insectivore, capturing flying insects on the wing. However, direct evidence supporting this trophic role has been lacking. Herein, I report on a specimen of C. centralis from seasonally-inundated swamp forest in the Caribbean lowlands of northeastern Costa Rica that provides valuable information on distribution, morphological variation, reproduction, and feeding habits of this species.