Abstract. Let G = SL(2, R) ⋉ R 2 be the affine special linear group of the plane, and set Γ = SL(2, Z) ⋉ Z 2 . We prove a polynomially effective asymptotic equidistribution result for the orbits of a 1-dimensional, non-horospherical unipotent flow on Γ\G.