This document evaluates the P-delta effect on the seismic response of tall structures. It presents the results of a static analysis of a 10-story reinforced concrete building carried out in ETABS software. The building was analyzed considering P-delta effects (non-linear static analysis) and without considering P-delta effects (linear static analysis) for seismic zones II and III. The results show that parameters like displacement, storey force, and moment are higher when P-delta effects are considered. Therefore, P-delta effect is significant and should not be neglected in the design of tall structures in seismic zones.