In current design practice, the responses of buildings and structures to fluctuating wind loads are usually separated into the background and resonant components, based on the assumption that these two components are not correlated with each other. The present paper proposes a new model for estimating the wind-induced responses of tall buildings, in which the background and resonant components and their cross-term are strictly defined and included. Therefore, the new model is more exact than the conventional ones. Comparisons are made for the along-wind and across-wind responses of tall buildings between this model and the conventional ones, based on a parametric investigation. The results show that the conventional models give results similar to those obtained from the new model for the along-wind responses, but generally underestimate the across-wind responses. Finally, some conclusions and useful suggestions are presented.