The parasiticidal activity of Antimycin A was tested against Cleidodiscus pricei Mueller, 1936 on fingerling and adult channel catfish, Ictalurus punctatus (Raf.). C. pricei was eliminated from two groups of fingerlings after 24 hr and 48 hr at Antimycin A concentrations of 0.5 μg, 1.0 μg, and 5.0 μg/liter. In two field tests, C. pricei was eliminated from adults after 48 hr of Antimycin A concentrations at 1.0 μg and 3.5 μg/liter.