This study assesses the seismic vulnerability of ductile reinforced concrete frames with masonry infill walls, utilizing nonlinear dynamic analysis of building models. The evaluation is based on structures designed and detailed according to Eurocodes. The research quantifies the effect of presence and configuration of masonry infill walls on the seismic collapse risk using Incremental Dynamic Analysis within the performance-based framework. Seismic vulnerability assessment indicated that of the configurations considered (bare, partially-infilled and fully-infilled frames), the fully-infilled frame had the lowest collapse risk and the bare frame is found to be the most vulnerable to earthquake-induced collapse. The study compares seismic vulnerability of reinforced-concrete frame structures with- and without infill. An Incremental Nonlinear Dynamic Analysis of the model planar reinforced-concrete frames exposed to a set of recorded ground motions was performed in order to evaluate their seismic vulnerability.