This research was conducted to determine the effects of sodium bicarbonate on the performance and some blood parameters of Japanese quails in the summer. Japanese quails were divided into four groups with three replications. A total of 420 Japanese quails were used in the experiment, lasting 6 weeks. In the experiment, four diets containing different levels of sodium bicarbonate (0, 0.1, 0.3 and 0.5 %) were utilized in the treatment. All the diets were identical in terms of energy, protein and other nutrients. Feed and water were consumed adlibitum. During the experiment, live weights and feed consumptions were recorded weekly. At the end of the experiment the average final weight and live weight gains of the groups were found to be 192.7, 192.7, 184.6, 186.8g; 162.1, 162.2, 153.4 and 155.9g (P>0.05); the feed consumption and feed efficiency ratio were 651.8, 650.2, 641.3, 662.3g; 3.98, 4.01, 4.15, 4.18 (P>0.05). respectively. The plasma calcium and phosphorus concentrations in the groups increased with the supplementation of sodium bicarbonate, but variations in the plasma Na, K, Cl, concentrations were found to be irregular. While blood pH was reduced (P<0.01) by sodium bicarbonate supplementation, the plasma concentrations of pCO2 and HCO3- increased (P<0.01).