This study was performed to evaluate the supplementation of α‐lipoic acid in diets on the growth performance of giant gourami juvenile. This study used the completely randomized design experimental method containing four diets treatments and four replications. The experimental diets comprised L0 as control (0.0 g/kg), L03 (0.3 g/kg), L06 (0.6 g/kg) and L09 (0.9 g/kg), which made as isonitrogenous and isocaloric diet. The experimental diets were given on the giant gourami juvenile (7.05 ± 0.08 g initial weight) for 60 days. The supplementation of α‐lipoic acid on L06 treatment significantly improved the feed intake, specific growth rate, feed conversion ratio, protein retention, lipid retention, liver lipid, liver glycogen and superoxide dismutase enzyme. On the other hand, the highest malondialdehyde, blood triglycerides and hepatosomatic index were obtained from L0 treatment (Duncan: p < 0.05). The water quality parameters (temperature, pH, DO, nitrite, nitrate and TAN) had no significant difference among treatments. This study concludes that the supplementation of α‐lipoic acid in diet improves the growth performance of giant gourami juvenile.