The aim of this study was to investigate the mammary infections present in dairy sheep farms through a study based on observation and palpation of the udder, as well as by milk cytology and bacteriological analysis. Clinical examination of 1006 lactating ewes revealed 11 (1.1%) with inflammatory signs. Screening the 995 ewes without inflammatory signs by the California Mastitis Test (CMT) for the prevalence of subclinical mastitis showed 59 (5.9%) as positive, with 68 udders affected. The bacterial species were identified from the 11 ewes with clinical mastitis and the 68 udders with subclinical mastitis. Among the bacteria isolated from the 11 ewes with clinical mastitis, Staphylococcus aureus was identified in six cases, Streptococcus uberis was identified in three cases and Eschérichia coli was identified in the other two cases. Among the bacteria isolated, coagulase negative staphylococci (CNS) were the most dominant of the organisms isolated (82.28%). It is suggested that due to the prevalence of mastitis, sheep farmers should be made aware of the problem in order to institute prevention and control measures to reduce the losses due to this disease in dairy ewes.