Abstract: We evaluated the potential of adult fairy shrimp, Streptocephalus sirindhornae, as live food for growth and enhancing the carotenoid contents in the giant freshwater prawn Macrobrachium rosenbergii. Completely randomized cultures of 6-months-old prawns were treated individually with 5 different food ratios (adult fairy shrimp to dry shrimp diet; 0: 100, 25: 75, 50: 50, 75: 25 and 100: 0) for 60 days in circular black plastic containers containing 20 L of water. The diet was fed at a rate of 3% of the prawn body weight per day. Each food concentration was experimented with 12 replicates and the whole experiment (5 treatments) using a total of 60 individuals. The results showed that the initial lengths (11.9-13.0 cm) and weights (23.20-31.65 g) of the experimental prawns with the 5 food ratios were not significantly different. However, length (0.87 cm) and weight (15.14 g) gains of the prawns fed pure fairy shrimp treatment (100: 0) were significantly different from those of the other dietary treatments (p<0.05). The prawns fed with the pure fairy shrimp had the highest specific growth rate of 0.84%, the lowest food conversion ratio of 1.38 and the highest survival rate of 84.75%. The prawns fed with pure fairy shrimp contained the highest total carotenoids of 4.144 μg g-1 of fresh weight with large amounts of astaxanthin and β-carotene, which was 2.8 times of those fed with pure dry diet treatment (p<0.05). Present results indicate improved growth performances and elevated carotenoid contents of prawns suggesting fairy shrimp as promising feeds in freshwater aquaculture.