AbstractThis study evaluated the effect of two commercial probiotics, zymetin, and super PS, on the culture environment, production, and economics of Macrobrachium rosenbergii aquaculture. The experiment was conducted using three treatments, including T1, probiotics applied in all culture phases; T2, during grow‐out; and a control (C). Prawns were fed commercial pelleted diets. Earthen ponds were used at a stocking density of two juveniles/m2. Water concentrations of non‐ionized ammonia and nitrite‐nitrogen were significantly lower (p < 0.05) in T1 than in T2 and C. Probiotic application significantly (p < 0.05) reduced phosphate content and balanced soil pH. Growth performance, condition factor, survival, protein utilization, and production were significantly higher in T1 followed by T2 compared to C by the end of grow‐out. Application of zymetin and super PS in all culture phases significantly (p < 0.05) reduced the feed conversion ratio in T1 compared to T2 and C. Positive allometric growth was observed in T1, whereas growth was isometric in C and T2. Probiotic treatment during all culture phases achieved the highest net returns to land, family labor, and management. Application of probiotics during the entire culture cycle could be the best practice for improving production and economics in M. rosenbergii aquaculture.