<p>This study experimentally investigated the effects of story-to-column poundings between adjacent RC buildings through shake table tests. Two scenarios were considered: (i) without pounding and (ii) with story-to-column pounding. The tests were conducted on two 1/2 scaled 2-story RC frames, employing natural ground motion records. The accelerations, displacements, IDRs, and modal parameters of the test specimens were comparatively investigated. The experimental results revealed that pounding significantly influenced structural responses, causing severe shear damage in the columns of the test specimen due to story-to-column collisions. Pounding represented a critical loading condition, inducing abrupt spikes in acceleration responses and resulting in damage. Moreover, pounding caused decreases in displacement responses but led to abrupt increases in base shear forces. This resulted in irregular and asymmetrical hysteresis loops, indicating varying energy distribution in the pounding direction due to repeated impacts. The modal parameters also changed significantly due to the impact, and the changes were observed earlier and more pronounced in the test specimen subjected to pounding.</p>