The main causes of degradation of water quality all over the world are pollutants. The heavy metals, organic molecules, micro organisms, sediments are main water pollutants, heavy metals are the most important pollutants of aquatic ecosystem. Industrial as well as environmental sources are the cause of metal contamination of water. By use of the polluted water and it lead to poisoning of fish, most of these heavy metals may accumulate in the body of fish. This research work was about the toxic effects of heavy metals and its presence in aquarium fish. Water was contaminated with different heavy metals e.g. Zn and Cu. The use of this water by fish affected the growth of Tiger barb (Puntius tetrazona). Effect of heavy metals (zinc and copper) on Tiger barb had not determined in Multan area. Samples were collected from different city area of Multan. Each sample of fish (Puntius tetrazona) was passed through the process of morphometry. Then they were dried and grinded. After grinding, samples were passed for ash formation. Then ash of each sample was dissolved to form solution. Then elemental analysis was performed by atomic absorption of spectrophotometer. Presence of zinc and copper was confirmed and its effects on growth were determined on Puntius tetrazonaby different statistical techniques. By the determination of these metals in this fish, could provide a way for new researchers doing work in this field on aquarium fish and it could help for the management of water pollution.