Milk is a cash crop for smallholders to convert low value forages, crop residues and family labor in to valued market commodity. The optimal milk productivity of cattle in Ethiopia has not yet been realized due to several constraints such as high prevalence of diseases as a result of poor disease control. Mastitis is the most prevalent disease in Ethiopian small scale dairy farms that cause a great economic loss by decreasing the milk production potential of the animal. Identifying the magnitude for the occurrence of the disease and the major risk factors helps to take remedy measures to decrease the occurrence and the spread of the disease in and between the farms. Thus this study has done to determine the prevalence of mastitis and the major risk factors of mastitis in Nazareth, Ethiopia. The conclusion and recommendations of this study are forwarded for the small scale dairy farmers in which the study has done.