The Schrodinger 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(n)((mu,nu)) (x), where mu > -1, nu > -1 and x is an element of[-1, +1]. The s-waves analytic solution is obtained. The numerical energy eigenvalues for selected H(2) and Ar(2) molecules are also calculated and compared with the previous models and experiments. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim