Roentgen stereophotogrammetric analysis (RSA) is an important technique for in vivo evaluation of joint kinematics and surgical outcome. However, its accuracy is highly affected by the experimental set-up. In this paper we present a new software environment for assessing the impact of calibration cage design on the accuracy of the reconstruction of 3D points, which can be easily used for preliminary evaluations also by non-expert users. The paper presents methods of the simulator and preliminary results in a clinical standard and custom environment. The software was realized using MATLAB and developed for the PC/Windows operating system. It is freeware under request to authors.