The present investigation deals with the correlation between optimally designed space frames and experimental results obtained from testing small-scale modeled three-dimensional frameworks loaded beyond the elastic limit. The optimum design procedure used was developed by M. Khalifa. A justification for using the linear optimization procedure as opposed to the non-linear one is presented. Efficient techniques for performing tests in small-scale modeled three-dimensional frames loaded up to failure are developed. Two small-scale modeled space frames are fabricated and tested; one subjected to vertical loads and the other to vertical and lateral loads. A comparison between the optimally designed space frames and the models tested is made. The results and conclusions are presented and discussed.