Milk is one of the food products which is used as vehicle of disease transmission to human being. This study was conducted to assess the quality of both raw and pasteurized milk produced by the five major milk processing plants in and around Addis Ababa. A total of 48 samples were taken from the five plants and triplicate of testes were conducted for each of them including tests for mycobacterium bovis and expressed in terms of mean (average).The result indicated that aerobic plate count ranges from 3.5 x105 to 4.6x106 cfu/ml in raw milk and 1.2x104 to5.2x10 5 cfu/ml in pasteurized milk. Escherichia coli which is used as indicator organism for the presence of pathogenic organisms was present in all raw milk and only detected in two pasteurized milk from plant B and plant E. It ranges from 4.33x104 cfu/ml to 5.37x105 cfu/ml in raw milk and 0 cfu/ml to 2.2x104 cfu/ml in pasteurized milk. Fecal coli forms which is an indicator of poor hygienic condition during milk handling ranged from 3.73x104cfu/ml to 6.67x105 cfu/ml in raw milk samples and 0 cfu/ml to 2.27x104 cfu/ml in pasteurized milk. Staphylococcal organisms was also detected in one sample of raw milk from the three plants and detected in two samples of pasteurized milk from the five milk processing plants. The results from the five milk processing plants indicated that there are some pasteurized milk found with bacterial load above the recommended value of 3-5 organisms/ml for coliform organisms by FMOH.From this result it is possible to conclude that consuming raw milk can lead to different infections. Key Words: Aerobic Plate Count, E. coli, Fecal Coliforms, Pasteurization