The conformational equilibrium of the 1,2-dichloroethane molecule in water has been studied with Monte Carlo free energy perturbation simulations. A polarizable model for the solute molecule combined with the nonpolarizable TIP4P model for the water molecules has been employed. The approach of only taking into account the polarization of solute produces a rather small increase of computational time with respect to the nonpolarizable simulations. Relative solvation free energies of the trans and gauche 1,2-dichloroethane conformations have been calculated through three perturbation paths which correspond to the progressive incorporation of three different intermolecular solute-solvent energy contributions (van der Waals, Coulombic, and polarization). This stepped procedure allows the separate analysis of the different interaction forces. The solute polarization is studied by introducing atom polarizabilities in the 1,2-dichloroethane molecule. Three polarization procedures which differ in the treatment of the intramolecular interactions among the polarization sites of the solute molecule have been analyzed. It is found that the inclusion of solute polarization produces a different reorganization of solvent molecules around the 1,2-dichloroethane conformations.