Environmental pollution is one of the most serious problems in the sphere of ecology. Rapid industrialization, discovery and development of new oil fields, modern agricultural practices, and other types of anthropogenic activities contribute substantial amounts of toxic heavy metals to the environment. Heavy metals are some of the prominent substances that pollute soil, water and air. Pollution by heavy metals is constantly rising, producing serious toxic effect on all forms of living organisms, and altering properties of soil and its biological activity. Excessive accumulation of heavy metals in plant products can have serious adverse effect on the quality and safety of food. Consumption of such products poses a potential risk to global food security and healthy lifestyle. This article examines the effect of heavy metals on plants and their enzymatic and metabolic processes, which ultimately leads to a decrease in overall productivity of plants.