A total number of 300 broiler chicks were randomly divided into five groups as follows: T1 (control group), fed on a basal diet containing (23%, 21.5% and 19.5% CP) for starter, grower, and finisher phases respectively; T2, fed on a diet with low protein 2% (21%, 19.5 %, and 17.5 % CP) without supplementation. T3 fed on T2 with (0.49, 0.074 and 0.07 %) digestible glycine. T4, fed on T2 with (0.98, 0.148 and 0.14 %) digestible glycine. T5 fed on T2 with (1.74, 0.222 and 0.21 %) digestible glycine in (Starter- Grower- Finisher phases), respectively. Results showed that the highest (p≤0.05) final body weights and weights gain were recorded by the control group followed by groups (T5, T4, and T3) and the differences between them were insignificant. The averages of feed intake, feed conversion ratio, and mortality ratio were not significantly affected by treatments. There were no significant effects for all treatments on total serum protein, triglycerides, uric acid, alanine aminotransferase and aspartate aminotransferase. Carcass traits showed no noticeable differences while, the abdominal fat weight was significantly (p≤0.05) increased in T5, T4, T1, and T3. Group of T1 showed an increase (p≤0.05) in crypts depth as compared to the chicks of T2. As well as the differences between T1, T3, T4 and T5 were insignificant. Results also indicated that total bacteria, Lactobacillus, Sterptoococcus, and Coliforms counts were insignificantly. Based on the findings mentioned above, it could be recommended supplementation of glycine with low-protein diets without adverse effects.