Water pollution is a significant environmental concern which has a negative effect on aquatic environment especially fish populations. Fish play very important roles in the health of aquatic environment and also as bioindicators in water quality. Contamination of water bodies, which may include heavy metals and pesticides, pharmaceutical and organic contaminants, and so on, may cause a considerable change in fish health and behavior, with short-term and long-term ecological effects. Examples of such heavy metals include mercury, cadmium and lead and they build up in fish muscles and lead to various physiological disturbances such as neurological impairments, liver dysfunction and immune malfunction. Any buildup of these pollutants not only causes direct damage to the fish, but also has indirect effects on the food chain as a result of bioaccumulation. Likewise, all those pesticides and pharmaceuticals found in agricultural and urban runoff can interfere with the hormonal and neurological systems of fish and cause changes in feeding behavior, reproductive failures, and diminished antipredator behavior. Further, organic pollutants, such as petroleum hydrocarbons and nutrient pollution, cause hypoxic effects in water bodies and suffocating aquatic life and preventing fish population growth and reproduction. These problems are further worsened by eutrophication which is instigated by the volume of nutrient runoff which further contributes to harmful algal blooms which further worsen the water quality. Other typical effects of pollution include behavioral changes in fish including disturbed swimming behavior, impaired social interactions as well as reduced foraging effectiveness. Such behavioral disorders may make them prone to predations, lower the chances of reproductive success, and long-range survival of fish populations. The paper is a review of the different pollutants that impact on the health and behavior of fish and it has been noted that there are physiological and behavioral changes as a result of various forms of pollution. This paper has highlighted the necessity of combating the problem of water quality to promote the health and viability of aquatic ecosystem based on the comprehensive effects of pollution on fish.