We examine a supersymmetric model in three dimensions containing two massless scalar superfields Φ1 and Φ2. The most generalized renormalizable interaction is characterized by two couplings if there is a discrete symmetry Φ1 ±Φ2; the renormalization group functions are computed to lowest order for these couplings. It is found that asymptotic freedom for one of these couplings occurs in a region of coupling-constant space.