Heavy metal pollution and high tropospheric ozone concentrations are two major environmental stresses that can significantly affect plant growth and productivity. In recent years, there has been increasing concern about the synergistic effects of these two stresses on plant physiology and biochemistry. This chapter explores the synergistic impacts of heavy metal-induced stress and high tropospheric ozone concentration on plant productivity, physiology, and biochemistry. Heavy metal pollution and tropospheric ozone are two major environmental stresses that affect plants globally. However, their combined effects on plants are less understood. The chapter reviews current literature on the physiological and biochemical responses of plants to heavy metal stress and high ozone concentrations and the interactions between them. It discusses the impacts of these stresses on plant growth, photosynthesis, and the antioxidant defense system. Overall, this chapter provides insights into the complex interplay between heavy metal pollution, high tropospheric ozone concentrations, and plant productivity, which can be used to develop effective strategies for improving plant growth and productivity in polluted environments.