The harmful effects of mercury lead to the inhibition of the growth and changes in biochemical constituents of food crops. Plants that are hyperaccumulators accumulate the mercury present in the air or in the soil which leads to growth retardation as well as affects the metabolic pathway regulation in plants. Several biochemical reactions happen due to the metallic accumulation such as lipid peroxidation, enzyme activation, chromosomal aberrations, and untimely cell death. Mercury causes a decrease in photosynthetic rate which turns the colour of the plants to pale yellow. Chlorophyll synthesis in the leaves was suppressed by mercury toxicity and increases the rate of oxidizing enzymes. Mitotic behavior as well as leakage of metabolites was adversely affected due to mercury toxicity. This review intends to understand the toxic effects occurring due to mercury accumulation and morphological, physiological, and biochemical changes occurring in different food crops.