This study was conducted to investigate the effects of supplemental medicinal herb mixture, laver powder and paprika powder in extruded pellet (EP) on growth and feed utilization of juvenile olive flounder. Triplicate groups of fish (average body weight of 19.6 g) were fed four experimental EPs containing 0.2% medicinal herb mixture (MHM), 1% laver powder (LP), 1% paprika powder (PP) and without supplementation (CON) for 9 weeks. Weight gain, daily feed intake, hepatosomatic index and condition factor were not influenced by dietary additives. Peed efficiency and protein efficiency ratio of flounder fed the diet containing laver powder were significantly higher than those of fish fed the medicinal herb mixture and paprika powder (P<0.05), but not significantly different from control group. The results of this study suggest that all tested additives in the dietary formulation did not affect growth and feed utilization of olive flounder.