Reinforced-concrete frames with masonry infill are composite systems, common in low and medium-high buildings, whose behavior under earthquake loads is difficult to predict. Because of that, most national codes ignore the contribution of infill to the structural response. In this paper, we determined the seismic behavior of infilled frames by using a numerical non-liner model (with various geometries and various masonry and r/c frame properties), using samples taken from the originally collected experimental data base on infilled frames “EDIF”. We then compared these experimental results to numerical models designed using recommendations from FEMA 356 (nonlinear model), Eurocode 8 (linear model), and other published methods (Stafford-Smith and Carter, Mainstone, Žarnić, Paulay and Priestley) in order to assess the most suitable, rational macro model for evaluating the behaviour of masonry infill in a reinforced-concrete frame during earthquake excitation.