A detailed seismic performance assessment procedure has been developed for reinforced concrete (RC) frame buildings with masonry infill walls. The procedure is based on member damage functions, in terms of interstory drift ratios. These functions are developed for the primary components, namely, columns, beams, and infill walls. For developing these functions, analytical investigations to determine the influence of several parameters on the damageability of components were combined with experimental data. A new approach has been developed to synthesize component damage states to determine the story and eventually the building level performance states. The procedure has been calibrated and compared with other procedures by predicting the observed performance of three buildings exposed to recent earthquakes in Turkey. It is concluded that the developed procedure can satisfactorily predict the damage experienced by most of the components of the studied buildings. Moreover, the procedure reasonably captured the observed building damage states. Accordingly, the developed procedure can be used for a reliable performance assessment as well as performance-based design of RC frame structures.