Amino triazole (3–amino–1,2,4–triazole) is a chemical which causes chlorosis in many plants. In many cases chlorosis is followed by the death of the plant. It is not known definitely whether the synthesis of chlorophyll is inhibited or whether chlorophyll is destroyed. Generally, only new growth, in which the pigment is being formed, shows chlorosis. This suggests that chlorophyll synthesis is affected. The chlorosis has been shown to be proportional to the amount of amino triazole applied. In order to establish a basis for further work, evidence on the translocation and fate of the chemical in several different plants is presented here.