This study was conducted in two experiments. Experiment 1 aimed to investigate the growth promoting and anti-oxidative effects of Azolla nilotica (AZN) and Spirulina platensis (SP) in Oreochromis niloticus. Seven fish groups (G1-G7), each in three replicates, were fed a basal diet (control), AZN 5%, AZN 10%, SP 0.5%, SP 1%, a mixture of Azolla nilotica 5% and Spirulina platensis 1% (AZN 5 %-SP 1% mix), and a mixture of Azolla nilotica 10% and Spirulina platensis 1% (AZN 10% - SP 1% mix), respectively, for 3 months. The results showed a significant increase in growth indices (weight gain, specific growth rate, average length gain, feed efficiency ratio), and a decrease in the feed conversion ratio in all supplemented groups compared to control. Hepato-somatic index in G4 and G5 groups, and intestinal-somatic index in G4 - G6, and in G5 and G6 were obviously higher than control. Spleno-somatic index and antioxidant enzymes (GSH-px, SOD and CAT) markedly increased in G5 and G6 compared to control. Significant increase (p