The uptake and translocation of radioactive 3-amino and-3-hydroxy- 1,2,4, -triazole in various plants has been investigated. The first compound is taken up and translocated much faster than the second one upon administration to a leaf. The rate of uptake through the roots or through the cut off stem is the same for the two compounds. The distribution of aminotriazole in the plants points to a translocation by the phloem system.