This study aims to examine the effects of magnetic water on behaviour, performance and some physiological parameters of Nile tilapia fish and the physicochemical properties of water. Forty-eight Nile Tilapia fish with 30.95±1.75g in weight were reared under normoxia conditions and classified into two groups (n=12/aquarium, 2 replicates). Group 1: fish raised in non-magnetized water (control). Group 2: fish raised in magnetic water using a magnetic field, 18000 Gauss (MW). Fish performance, behavioural and physiological responses were examined as well as water quality parameters of the fish aquarium were measured. At the end of the experiment, fish (n=6/aquarium, 2 replicates) of two groups were exposed to 8 hours of hypoxia. Fish behaviour was recorded and water quality parameters of the fish aquarium were measured. Results revealed that the body weight and body weight gain of fish were significantly (p<0.05) increased, however, feed conversion ratio was decreased for fish reared under the use of water magnetization. Magnetic water fish showed high comfort behavioural activities with low surfacing and eliminative behaviours. Water magnetization improved significantly the dissolved oxygen, ammonia, and turbidity of the fish aquarium. Magnetic water fish showed high total protein and globulin with a lower plasma glutathione reductase (GSH). Fish of magnetic water showed a significant increase in resting and a decrease in surfacing, chasing, and biting with lower plasma cortisol when exposed to hypoxia condition. The dissolved oxygen of magnetic water was significantly more than the dissolved oxygen of normal water after hypoxia exposure. These findings suggest that using magnetic water has significant performance and behaviour benefits, as well as reduced hypoxia stress effects in Nile tilapia fish.