Mastitis is one of the most costly diseases of dairy animals. Bacteria constitute the most common etiological agents of mastitis. The present study was designed to determine the prevalence of mastitis in buffaloes and to determine the susceptibility to various antibiotics. Milk samples collected from buffaloes maintained at Livestock Experimental Station Bhunikey were subjected to screening by using Surf Field Mastitis Test. The samples found positive were cultured on culture media such as Blood agar, MacConkey’s agar, Staphylococcus medium No. 110 and Nutrient agar. The isolated organisms were identified and subjected to 8 commonly used antibiotics for determination of antibiotic sensitivity during period of 6 months (Jan-June, 2007) Eight hundreds milk samples from buffaloes were tested for mastitis out of which 75 (9.32%) were found positive. Staphylococcus aurous was the most frequently isolated pathogen (44%) followed by Streptococcus agalactiae (22%), E.coli (16%) bacillus spp. (4%) and mixed growth (14%). Norfloxacin, Gentamycine and Choramphenocol were found most effective drugs among the 8