A description is made of a new trichurid species of the subfamily Capillariinae, Aonchotheca moraveci sp. n., parasitizing the stomach of the long-fingered bat, Myotis capaccinii (Bonaparte, 1837), in Spain. The male presents two caudal lateral alae, a membranous caudal bursa supported by two forked expansions, a spicule 405-536 microns long and a non-spiny spicular sheath. The female has a vulvar appendage and the egg-shell surface presents a fine striation, only scarcely appreciable at the polar plugs.