Structural configuration is one of the important parameters to control the performance of multi-storeyed structures subjected to lateral loads. On other hand, also the economy of multi-storeyed structures depends on the spacing of columns. The present investigation is aiming to find the effect of bay spacing on the performance of medium to high rise RC structures subjected to lateral loads. In this regard, a computer- based analysis is carried out for 10, 15, 20, 25 and 30 storied bare frame structures. Each structure performance under lateral loads is investigated for 4 types of bay spacing i.e. 5m, 6m, 7.2m and 8.64m, with an increment of 20% bay space each time. For each structural model, the behaviour of the structure is examined in terms of storey displacement, storey drift and base shear. The quantitative parametric comparison is done between all the models mentioned and has identified the optimal size of the bay spacing to suit the aspect ratio of the structure is proposed.