Objective : This study aimed to assess the effect of dietary methionine supplementation on the productive performance of growing pigs. Methods : A total of 200 Large White pigs including 100 sows and 100 castrated with an average body weight of around 41.09 ± 7.08 kg were assigned to five treatments of basal diet supplemented with 0% (M0), 0.25% (M0.25), 0.50% (M0.50), 0.75% (M0.75) and 1% (M1) of methionine having 4 replicates of 10 pigs each. All treatments were subjected to the same prophylactic plan. Data were collected on feed intake, body weights and body measurements, such us back length, thoracic perimeter and height at the withers. The data collected were analyzed using one-way ANOVA. Results: This study showed a significant reduction in feed intake in M0.50 and M0.75 pigs compared to the other treatments. On day 60, pigs in M1 treatment showed significantly lower body weights than the pigs in M0.50. Pigs in the M0.75 treatment had the lowest feed conversion ratio compared to M1 treatment. The economic evaluation revealed that M0.50 and M0.75 treatment groups had the best production costs. Conclusion: Supplementing diets with 0.50% methionine resulted in better production costs in Large White pigs and this is strongly recommended to farmers.