This book is aimed at investigating the microbiological quality of 'Ergo' an Ethiopian traditional fermented milk. To evaluate microbial quality of Ergo from cafeterias and restaurants in Bahir Dar town, thirty samples were collected and subjected to microbiological examination. The results showed that aerobic mesophilic bacteria Salmonella, lactic acid bacteria, S.aureus, and yeasts and molds counts were high. From a total of 30 samples, 26 (86.66%) of aerobic mesophilic bacteria count exceed the guide line (<105 cfu/ml) for ready to eat food. Salmonella was detected in 23 (76.66%) samples. Similarly, S. aureus was detected in 19 (63.33%). All the tests in bacterial counts indicated that the microbiological quality of Ergo prepared for consumption was hygienically poor and this call for careful hygienic measures during production and handling of milk.