This study reports the occurrence of sheep epididymitis and the isolation of Actinobacillus seminis in the state of Pernambuco, Brazil. An increase in volume of the testicles and epididymis, pain and increase in the local temperature at palpation, and bilateral testicular atrophy were clinically observed. After slaughter, the presence of purulent content in the epididymis was found. In microscopy of the testicles, coagulation necrosis and calcification of seminiferous tubules, thickening of the tunica albuginea, fibrosis, inflammatory infiltrate with predominance of lymphocytes between seminiferous tubules and incipient mineralization of tubules was observed. In the epididymis, intense proliferation of conjunctive tissue and fibrosis around the epididymal ducts was found. The diagnosis of epididymitis by Actinobacillus seminis was confirmed with association of the clinical findings, isolation and identification of the bacteria, as well as through histopathological exam.