A new second-moment closure model for turbulent scalar transport is proposed on the basis of the correlation coefficients between the flow variables and their derivatives that appear in the scalar-pressure gradient and dissipation terms of a turbulent scalar flux. Since these correlation coefficients should respond sensitively to a change in any of the time scales characteristic of turbulent transport, the model is given as a function of their ratios, which can be written in terms of turbulent Reynolds number, (Re-t = k(2)/nu epsilon),Prandtl number (Pr = nu/alpha) and time scale ratio (R = (k(theta)/epsilon(theta))/(k/epsilon)). The conventional modeling methodology, i.e. the high Reynolds number hypothesis is abandoned,although the proposed model asymptotes to the well-established model expression in high Reynolds/Peclet number flows. As a result, the scalar fluxes are predicted very well in the homogeneous as well as wall-shear flows over a wide Prandtl number range.