Damage to forest plantations, fruit orchards, and nurseries by mice of the genus Microtus has caused serious economic losses, particularly in northern and eastern North America (Cayford and Haig 1961; Jokela and Lorenz 1959; Libby and Abrams 1966; Littlefield, Shoomaker, and Cook 1946; Sartz 1970). In southeastern United States damage to plantations of pines is increasing in importance. Two species of Microtus, the prairie vole (Microtus ochror;aster) and the pine vole (M. pinetorum), are widely distributed and capable of inflicting serious damage. This paper reports on the results of a field test designed to study the usefulness of two rodenticides for controlling prairie voles in Virginia pine plantations in Tennessee. The specific formulations tested were (I) whole oat (A vena sativa) groats coated with 1.5% and 1.0% solutions of zinc phosphide, and (2) water repellent paper tubes with an inner lining of cracked corn (Zea mays) treated with Prolin, an anticoagulant poison (0.05% warfarin and 0.05% sulfaquinoxaline).