Cases of periodontitis in sheep from the Agreste and Zona da Mata regions of Pernambuco, Northeastern Brazil, are described. Information on breed, age and sex of affected animals as well as clinical and pathological aspects of the disease were obtained during farm visits. Fifteen animals from a total of 450 Santa Inês sheep, aged between three and twelve years, showed low body condition score, dull coat, and difficulty in feeding followed by pain on palpation of the mandibular region. Physical examination of the oral cavity of affected animals and post mortem findings of slaughtered individuals revealed varying degrees of periodontitis, wear, fracture, mobility, and loss of teeth associated with gingival retraction, presence of biofilm and food packing between incisors, premolars and molars teeth. Increased mandibular volume was observed in eight animals and, in two of them, an abscess fistula, exclusively in mandibular teeth. The occurrence of periodontitis in sheep had not been recorded until now in Northeastern Brazil and, thus, this is the first description of cases in the region.