A study was designed to detect the mastitis and its mastitogens in Bhag-nai cows at district Naseerabad, Pakistan. Milk samples were collected from Bhag-nari cows. All information of milk samples (n=323) were collected randomly on the basis of designed performa (Annexure.1). Two to three strips of milk from each quarter were drawn on the floor surface to examine the presence of pus, blood clots, flakes and change in color. Strip cup test was applied to detect the clinical mastitis. Surf Field Mastitis Test (SFMT) was used for the detection of subclinical mastitis in Bhag-nari cows. Aseptic techniques were applied by using cotton swabs dipped into 70% ethanol to clean and disinfect teat end. Sterile tubes of 10ml capacity were used to collect the milk samples. The positive milk samples were kept immediately in an icebox cooler and transported to lab (CASVAB) in Quetta. Primarily each milk sample was cultured on Nutrient agar by spread out technique. Mannitol salt agar was used to culture the Staphylococcus aureus. Multiple streaking was applied to isolate the selected bacteria. On the basis of culture characters, microscopic morphology, staining method and biochemical tests bacterial isolates were identified. Prevalence of mastitis in Bhag-nari cattle in Naseerabad, Balochistan was 15.79%. Areas wise the prevalence of mastitis was 18.5%, 16.2%, 14.1% and 12.9% in DM Jamali, Chattar, Baba kot and Tamboo, respectively. Age wise prevalence in the study was 14.29%, 19.63%, 17.58% and 4.88% in age group of 3-5 years old, 6-8 years, 9-11 years and above 11 years, respectively. On the based on number of calving there was significant difference (P