A total of 1164 indivedual quarter milk samples collected from220 and 71 apparently healthy CO\Vs and buffaloes respectively wereexamined bacteriologically as well as by screening tests, for detection ofsubclinical mastitis.The incidence percentage of subclinical mastitis among lactatingcows and buffaloes were 45.45% and 32.39% respectively.Bacteriological examination of the milk samples revealed thatStrept. dysgalactiae and E. coli were the most prevalent microorganismsisolated from subclinical mastitis in dairy Fresian cows with an incidenceof 13.2% and 10.9% respectively. While Strept. faecalis, Staph. aureus,Staph. xylosus, Staph. epidermidis and Pseudomonus aeuroginosa couldbe detected in 3.20/0, 3.2%, 2.7%,1.4% and 0.9% of samples respectively.