Objective: The aim of this study is to examine the antimicrobial activity of garlic oil to extend the shelf life of ground mutton stored aerobically at 4 ^oC for 15 days through its effect on the aerobic plate count and Enterobacteriaceae count that contaminate the meat during its preparation. Design: Observational controlled study. Samples: 7200 g of fresh mutton Procedures:meat sampleswere divided into four equal groups (600 gm each), three, groups were treated with different concentrations of garlic oil (250, 360, and 600 mg/kg) and the last group (without any addition) as a control. The treated samples were thoroughly mixed with garlic oil by hand (with sterile gloves), then the meat of each group was packaged separately in sterile polyethylene bags, marked, and stored aerobically in the refrigerator at 4 ^oC for 15 days and subjected to microbiological analyses and sensory evaluation. Results:there was a significant decrease in aerobic plate count and Enterobacteriaceae count of treated meat samples in comparison with the untreated samples. Additionally, the use of garlic oil at concentration of 600 mg/kg meat has higher effect than 250 mg/kg and 360 mg/kg during the period of storage. Furthermore, garlic oil also enhanced the sensory characteristics of treated the ground mutton. Conclusion and clinical relevance: we suggest that the addition of garlic oil to fresh mutton during cold storage is potentially useful in improving its quality and extending its shelf-life.