The Schr¨odinger equation for the rotational-vibrational (ro-vibrational) motion of a diatomic molecule with empirical potential functions is solved approximately by means of the Nikiforov-Uvarov method. The approximate energy spectra and the corresponding normalized total wavefunctions are calculated in closed form and expressed in terms of the hypergeometric functions or Jacobi polynomials P(μ,ν) n (x), where μ > −1,ν > −1 and x ∈ [−1, +1]. The s-waves analytic solution is obtained. The numerical energy eigenvalues for selected H2 and Ar2 molecules are also calculated and compared with the previous models and experiments.