Heavy metals represent a group of dangerous pollutants, to which is paid close attention. Many heavy metals are essential as important constituents of pigments and enzymes-mainly zinc, nickel, and copper. However, all metals, especially cadmium, lead, mercury, and copper, are toxic in high concentrations because they disrupt enzyme functions, replacing essential metals in pigments or producing reactive oxygen species. The toxicity of less common heavy metals and metalloids, such as thallium, arsenic, chromium, antimony, selenium, and bismuth has been investigated. Here we review the phytotoxicity of thallium, chromium, antimony, selenium, bismuth; and other rare heavy metals and metalloids such as