Water plays a crucial role in human activities. With the revolution in industrialization, water is the key element being immensely used. Due to industrial activities, many toxic substances enter water bodies, resulting in water pollution. Treatment of industrial effluents needs to be carried out efficiently for sustainable development. Otherwise, it will affect aquatic life and human health. Heavy metal contamination in water is considered to be a major environmental issue as it leads to an adverse effects on living organisms. Heavy metals are the one that have high density and even low concentrations of these metals will lead to toxicity. Heavy metals such as mercury (Hg), cadmium (Cd), chromium (Cr), arsenic (As), and lead (Pb) are commonly found contaminants. Several methods are employed to effectively remove these ions from the wastewaters, including chemical precipitation, membrane filtration, coagulation, adsorption, flocculation, ion exchange, and reverse osmosis. Among them, ion exchange sorbents are more reliable, effective, and appropriate materials for treating heavy metal ions. A comprehensive information about the removal of heavy metal ions from water and wastewaters using various polymer cation exchanger sorbents is included in this chapter.