This experiment was conducted to estimate the influence of γ-aminobutyric acid (GABA) on growth performance, nutrient digestibility, blood profiles, meat quality, and backfat in finishing pigs. A total of 100 mixed finisher pigs [(Landrace × Yorkshire) × Duroc] were randomly allotted to two dietary treatments for 10 weeks, the average initial body weight was 52.03 ± 1.08 kg. Dietary treatments consisted of supplementation of GABA to 0.05% of the basal diet (GAB) and a CON (basal diet) without supplementation . Each treatment had 10 replicates with 5 pigs per pen (three gilts and two barrows). Measurements were made at three time period: weeks 1 - 5, weeks 5 - 10 and overall experimental period. Compared to CON, the pigs fed GABA had average daily gain (ADG) increases among phases (p < 0.05). Average Daily Feed Intake ADFI increased during the overall experimental period (p < 0.05). The digestibility of Dry Matter (DM) increased. The concentration of epinephrine decreased at 5th and 10th weeks (p < 0.05), meanwhile, cortisol decreased at 10th week (p < 0.05) in GAB treatment. Otherwise, the pigs’ GABA supplementation had no effect on meat quality and backfat thickness (p > 0.05). We conclude that a dietary supplementation of GABA at 0.05% improves growth performance and the digestibility of dry matter, while reducing the stress response of finishing pigs.