ABSTRACT. Nascimento C.G., Correia T.R., Oliveira G.F., Coumendouros K., Moraes P.A., Calado S.B., Bragaglia G.N., Rosa S.C., Toma S.B. & Scott F.B. [Eprinomectin 1% Inyectable in control of Dermatobia hominis in naturally infested cattle.] Eprinomectina 1%Injetável no controle de Dermatobia hominis em bovinos naturalmente infestados. Revista Brasileira de Medicina Veterinária, 37(Supl.1):81-84, 2015. Programa de Pós-Graduação em Ciências Tecnologia e Inovação em Agropecuária, Universidade Federal Rural do Rio de Janeiro, Campus Seropédica, Ecologia, BR 465 Km 7, Seropédica, RJ 23897-970, Brasil. E-mail: firstname.lastname@example.org The aim of the study was to evaluate the effectiveness of injectable eprinomectin 1% on the control of Dermatobia hominis in naturally infested cattle. We selected 20 calves, crossbred Gir and Holstein breed, male and female, separated into two groups, control and treated. The control group of animals received no treatment, while the animals of the treated group received eprinomectin formulation of 1% at a single dose of 1 mL/50 kg body weight (200mcg of eprinomectin/kg) per injectable route. On days +7 and +14 a count of the total number of live larvae of D. hominis on both sides of the animal for the purpose of evaluation of the effectiveness was performed. Statistical analysis of average living larvae of D. hominis counted among the groups, control and treated, showed that there was a significant difference (p ≤ 0.05) between groups on days +7 and +14. The investigational product showed an efficacy of 100% results in both experimental days. The injectable eprinomectin 1%, shown to be effective in cattle naturally infested by D. hominis (the human bot fly).