The antioxidant effects of oregano essential oil and tannic acid combinations on ground chicken breast and thigh meats were studied. Six treatments, including: 1) control (none added), 2) 100 ppm oregano essential oil + 5 ppm tannic acid, 3) 100 ppm oregano essential oil + 10 ppm tannic acid, 4) 200 ppm oregano essential oil + 5 ppm tannic acid, 5) 200 ppm oregano essential oil + 10 ppm tannic acid, and 6) 5 ppm butylated hydroxyanisole (BHA) for breast or 14 ppm for thigh meat, were prepared. Cooked meat samples were individually vacuum-packaged in oxygen-impermeable vacuum bags and then cooked in-bag to an internal temperature of 75°C. After cooling to room temperature, the cooked meat was re-packaged in new oxygen-permeable bags and stored at 4°C for 7 days. Cooked ground chicken meats were analyzed for lipid and protein oxidation and volatiles at 0, 3, and 7 d of storage. The significant differences among the treatments were very clear in cooked meat samples: Thigh meat patties showed higher 2-thiobarbituric acid reactive substances (TBARS), total carbonyl, and volatiles content compared to the breast meat during storage. A combination of 200 ppm oregano oil with 10 ppm tannic acid showed the most significant effects (P < 0.05) on TBARS, total carbonyl, and off-odor volatile formation for both breast and thigh meats. Oregano oil (200 ppm) and 10 ppm tannic acid combination also showed positive effects on the sensory scores of chicken thigh meat. In conclusion, the combination of 200 ppm oregano oil and 10 ppm tannic acid could be a good replacement for the synthetic antioxidants in ground cooked chicken meat.