Cadmium is an important pollutant in the environment, toxic to most organisms and a potential threat to human health: Crops and other plants take up Cd from the soil or water and may enrich it in their roots and shoots. In this review, we summarize natural and anthropogenic reasons for the occurrence of Cd toxicity, and evaluate the observed phytotoxic effects of plants growing in Cd-supplemented soil or nutrient solution. Cd-induced effects include oxidative stress, genotoxicity, inhibition of the photosynthetic apparatus, and inhibition of root metabolism. We explain proposed and possible interactions between these modes of toxicity. While discussing recent and older studies, we further emphasize the environmental relevance of the experiments and the physiological response of the plant.