Pollution of the environment by toxic metals in recent years has accelerated dramatically due to rapid industrial progress. Heavy metals when taken up in amounts in excess of the normal concentration produce lethal effects on plants, on microbes, and directly or indirectly on the human health. Deleterious impact of metals on plants includes the reduction in germinability of seeds, inactivation of enzymes, damage to cells by acting as antimetabolites, or formation of precipitates or chelates with essential metabolites. Heavy metals also show unconstructive effects on other physiological processes like photosynthesis, gaseous exchange, water relations, and mineral/nutrient absorption by plants. These adverse effects may be due to the generation of reactive oxygen species which may cause oxidative stress. The impact of heavy metals on germination of legume seeds and different physiological events of plants with special reference to leguminous plants grown in distinct agroecological niches is highlighted.