C. Allard, R. Froese A Mourre estimate for a Schroedinger operator on a binary tree. (231K, PostScript) ABSTRACT. Let G be a binary tree with vertices V and let H be a Schrodinger operator acting on l^{2}(V). A decomposition of the space l^{2}(V) into invariant subspaces is exhibited yielding a conjugate operator A for use in the Mourre estimate. We show that for potentials q satisfying a first order difference decay condition, a Mourre estimate for H holds.