The aim of the work is to evaluate the influence of masonry infills on the seismic behaviour of reinforced concrete frames designed according to Eurocode 8 provisions as bare frames. To this purpose, non linear dynamic analyses of a twelve storey–three bay plane frame are performed considering four different infills configurations, named bare, fully infilled, open ground storey and open seventh storey frames. Artificially generated and recorded near fault ground motions are used in the numerical analyses. The accelerograms are scaled to attain the same intensity of the design one. The analyses are performed by means of a finite element code with fiber elements for the modelling of columns and beams. The infill walls are modelled through equivalent diagonal no tension struts, of which the constitutive law and the hysteretic behaviour are described in detail in the article. The structural response is evaluated through several parameters, such as top horizontal displacement, maximum interstorey drift and dissipated energy. The main inference is that the effect of uniformly distributed infills on the seismic performance is beneficial due to the additional strength, stiffness and energy dissipation capacity provided. The presence of an open storey may change this general conclusion, especially in the open seventh story model. Anyway the building retains strength and ductility resources when subjected to earthquakes of the same intensity of the design one.