Significant amounts of heavy metals have been added to the soils globally due to the natural as well as anthropogenic activities. The heavy metal accumulation in crops may cause serious disorders in plants as well as in human beings. Therefore, investigation on heavy metals toxicity is remaining an area of scientific interest. In order to increase crop productivity and minimizing health hazards of heavy metals toxicities it is necessary to understand their mechanisms of toxicity. In this way, osmolytes such as proline is endogenous organic substance which regulates normal growth and development of plants, grown under metal contaminated urban and peri-urban areas. Therefore, application of proline and/or manipulation of gene(s) enhance the activity of enzyme(s) and their biosynthetic pathways have also been found to be much effective in mitigating heavy metal toxicity. In this review, impact of heavy metal toxicity on plants and adaptation strategies of plants with special role of proline have briefly been discussed.