A new fossil fish, Vachalia moraviensis, gen. et sp. nov., is described based on a single articulated specimen collected from lower Oligocene deposits exposed in the vicinity of Kelč, Czech Republic. The morphological analysis of the specimen reveals a series of features that unambiguously support its recognition as a new member of the alepocephaliform family Platytroctidae. Vachalia moraviensis, gen. et sp. nov., is characterized by a very large head; elongate and ribbon-like body; two premaxillary tusks, of which the posterior is distant from the anterior one and almost perpendicular to it; posterior border of the maxilla behind the orbit; two supramaxillae; nine branchiostegal rays; 22 abdominal and 18 or 19 caudal vertebrae; dorsal fin with 16 or 17 rays; pectoral fin reduced and composed of approximately 12 short rays; pelvic fin larger than pectoral fin; and photophores (apparently) absent. The specimen described herein represents the first and only known fossil belonging to the family Platytroctidae based on articulated skeletal remains.