© 2023 Elsevier LtdOn October 30th, 2020, at 14:51, İzmir was hit by an Mw = 6.6 magnitude earthquake. The earthquake caused significant damage in Bayraklı, Karşıyaka, and Bornova districts. Structural damage and life losses were observed to be concentrated in Bayraklı region of İzmir. Twelve reinforced concrete buildings were collapsed in Bayraklı. Previous devastating earthquakes have shown that the damaged buildings are not very high-rise buildings, generally the lower storeys of which are car parks, and commercial enterprises, and there are no infill walls on the ground storeys. The same happened in the buildings destroyed in the October 30, 2020, İzmir earthquake. In this study, the effects of infill walls in reinforced concrete buildings under earthquake effects were investigated. For this purpose, a building damaged in the 2020 İzmir earthquake was examined. The building discussed in the study was modeled in the SAP2000 V22 finite element program in two different ways, with and without infill walls, using the real parameters of the building. As a result of the study, the results of the analysis were compared, and it was observed that the infill walls positively affected the features of the building, such as period, ground storey shear force, column bearing capacity, inter-story drift ratio, and base shear forces on the ground storeys, and increased the base shear force.