We present the first light curves in the infrared j and K filters, obtained in different runs during 1990, 1991, and 1994. The solutions of these IR light curves together with the previous determinations, gathered from visual light curves and spectroscopic studies, finally yield stellar parameters that can be accepted with confidence. The study of the (V-λ) observed colors, by comparison with tabulated colors of normal stars, indicates that they correspond to those expected if RT And components have GO V and K2 V spectral types. The comparison `with ATLAS stellar atmosphere models gives effective temperatures about 6000 and 4900 K, for the primary and secondary star, respectively. From the visual-infrared photometry there is no evidence of an IR excess in the system, and its distance is determined to be 103 pc. We have compared the absolute stellar parameters derived from the light curve solutions with new evolutionary models for solar composition, and discussed the age and evolutionary state of this binary system. While the mass and radius of the primary star locates it close to the main sequence, with an age of about 1.4 × 109 yr, the secondary star seems to be oversized for its mass, and some sort of interacting episode in the evolutionary history of this detached binary is not discarded.