A study was undertaken to investigate the effect of dietary supplementation of turmeric (Curcuma longa) powder on the performance of commercial broiler chicken. This experiment was conducted at the Instructional Livestock Farm Complex, HICAST, Kirtipur, Nepal for 42 days from 20th May 2023 to 30th June 2023. A total of 200 day-old commercial broiler chicks comprising 50 chicks in each group with uniform body weight were randomly divided into four groups viz. T0 (diet with 0% Turmeric powder as control), T1 (diet with 0.5% Turmeric powder), T2 (diet with 0.75% Turmeric powder), and T3 (diet with 1% Turmeric powder). Experimental birds were provided adlib starter feed for first 21 days and continued with the finisher feed for another 21 days and had easy access to drinking water. Feed intake was recorded daily and body weight gain was measured at 7-day intervals. The final body weight was significantly higher (p<0.05) in the T1 group (2046.89 g) followed by T0 (1807.2 g), T2 (1773.55 g), and T3 (1742.323 g) respectively. With respect to overall FCR, the T1 group showed the best FCR value of 1.58 followed by T2 (1.74), T3 (1.86), and T0 (1.91). This study revealed that increased body weight improved FCR and highest BEPI in chicks fed with 0.50 % Turmeric powder. Thus, it can be recommended that Turmeric powder can be used as a natural feed additive in feed at the level of 0.50% to improve the overall performance of broiler chicken.