Introduction: Heavy metals such as manganese (Mn), magnesium (Mg), chromium (Cr), and nickel (Ni) negatively impact plant growth and productivity. Understanding plant responses to heavy metal stress is crucial for developing strategies to mitigate these effects in agriculture. Aim/Objectives: This study aims to investigate the impact of various heavy metals (Mn, Mg, Cr, and Ni) on the physiological and morphological responses of Vigna Mungo (L.) Hepper. Key objectives include evaluating the effects of different concentrations of these heavy metals on plant growth, productivity and photosynthetic efficiency. Method/Materials: A field experiment was conducted using a series of pots filled with soil, treated with different concentrations of MnCl2, MgSO4, Cr2O3, and Ni. Control samples without heavy metals were also maintained. Key parameters, including plant height, number of branches, number of pods, pod length, fresh and dry weight of pods, number of seeds per pod, weight of 100 seeds, root nodules, and chlorophyll content, were recorded and statistically analysed. Results: Heavy metal stress significantly inhibited plant growth and productivity, with decrease in plant height, number of branches, pods per plant, pod length, fresh and dry pod weight, and seeds per pod. High chromium concentrations prevented pod formation. Root nodules decreased, affecting nitrogen fixation. Chlorophyll content decreased in Mn, Ni, and Mg-treated plants but unexpectedly increased at higher Cr concentrations, indicating complex interactions with chlorophyll synthesis. Discussion: The findings show that heavy metal stress significantly inhibits plant growth and productivity, consistent with previous studies. Symptoms such as stunting, and chlorosis indicate disruptions in metabolic processes. This study underscores the need to monitor and manage heavy metal levels in agricultural soils to protect crop health and productivity. Developing soil remediation strategies and heavy metal-tolerant plant varieties is crucial for sustainable agriculture. Further research is needed to understand plant responses to heavy metal stress and enhance plant tolerance.