ABSTRACT. Silva D.D., Lambert M.M., Coelho C.N., Batista L.C.S.O., Nunes T.A.P., Correia T.R., Scott F.B. & Fernandes J.I. [Efficacy of 1% flumethrin “spot-on” in naturally infested rabbits for Psoroptes ovis.] Eficácia da flumetrina 1% “spot-on” no controle de Psoroptes ovis em coelhos naturalmente infestados. Revista Brasileira de Medicina Veterinária, 37(Supl.1):1-5, 2015. Curso de Pós-Graduação em Ciências Veterinárias, Instituto de Veterinária, Anexo 1, Universidade Federal Rural do Rio de Janeiro, Campus Seropédica, Ecologia, BR 465 Km 7, Seropédica, RJ 23897-970, Brasil. E-mail: vetjulio@ yahoo.com.br Due the fact that considered docile, small and easy to handle, domestic rabbits have been bred as pets. Skin diseases caused by parasitic agents are common. Sometimes asymptomatic, infestation by mites species Psoroptes ovis can cause inflammation of the ear canal, ear drooping, crusting and pruritus. The goal of the study was to evaluate the efficacy of pyrethroid flumethrin applied directly into the auditory canal for treatment of P. ovis in naturally infested rabbits. 12 rabbits divided into two groups were used: Group 1, control group and group 2, treated with 1% flumethrin (1mg/kg) as a single dose. The clinical and parasitological evaluations of the animals were performed on days 0, +3, +7, +14, +21, +28 and +35 after treatment. The effectiveness of P. ovis was 83.33% at day +3; +21; +28 and +35, for 100% only on days +7 and +14. All rabbits in the treated group showed high clinical, except an animal that had four score on day 0. In the control group, all animals showed an increase in the score and worsening of symptoms. The flumethrin 1% pour-on at a dosage of 1 mg / kg administered directly into the ear canal was effective in controlling P. ovis in naturally infested rabbits without causing no adverse reactions in treated animals.