A study was undertaken on the effect of probiotic bacteria, belonging to genera Bacillus and Streptococcus, on survival, growth and production of wild-collected red snapper, Lutjanus argentimaculatus in marine cages for a period of 90 days. Wild-collected juvenile fish with an initial biomass of 0.79 kg/m³ were stocked in marine cages at Karwar, India. All the fish (control and probiotic treated) were fed with pellet feed at 10% fish biomass. The feed was supplemented with multi-strain probiotic combination (T₁) and with single-strain probiotics (T₂ and T₃). Growth, survival of fish, and microbiological parameters were monitored at fortnightly intervals. After 90 days of culture, the final mean weight (g), Absolute Growth Rate (AGR g/day), and Specific Growth Rate (SGR%/day) of fish were recorded as 250 ± 0.5 g; 2.23 ± 0.012 g/day; 0.79 ± 0.052%/day, respectively, in T₁. A significant difference (P < 0.05) among the different treatments was recorded, and T₁ showed a higher growth rate. The highest survival rate was recorded in T₁ and T₂ and varied significantly among the treatments (P < 0.05). Microbiological analysis of fish gut revealed the presence of Bacillus species as the dominant group in T₁, followed by T₂. A significant variation (P < 0.05) was recorded in total bacterial and Bacillus loads among all the treatments. The results of the study indicated that the application of 0.1% of multi-strain probiotics as a supplementary diet is economically viable and also enhances the survival, growth, and production of cage-cultured L. argentimaculatus.