Two trials were conducted with two sizes, grow-out (80.0 mg b.w.) and fattening (5.0 g b.w.), of Penaeus semisulcatus to compare the production and yield of shrimp cultured at different stocking densities within an indoor running-seawater system. In the first experiment, postlarvae were cultured at 50, 100, 150 and 200 m−3 for 68 days, while in the second experiment, juveniles were cultured at 24, 50, 74 and 100 m−3 for 126 days. The results of the two experiments showed significant decrease in weight of shrimp as the stocking density increased. During the grow-out stage, no statistical differences were observed on survival rates among the shrimp stocked at different densities. Thus, as the primary factor to consider at this stage is the number of shrimp produced, it is recommended to use a density of 200 shrimp m−3. During the fattening stage, the survival rate at the highest density was statistically lower than the other three densities. The mean yield was 437.02, 869.16, 1217.62 and 1446.78 g m−3 for shrimp stocked at 24, 50, 74 and 100 m−3 respectively. Although the average harvest size of juveniles at the lowest stocking density was statistically higher than those stocked at the highest stocking density, both sizes (18.12 and 16.67 g) will be classified as one size group in the market, i.e. medium. As the yield significantly increases as the stocking density is increased, it is therefore recommended that the stocking density for the fattening stage be 100 shrimp m−3.