Roentgen stereophotogrammetry is based on radiographic examinations of calibration cages and object markers implanted in the skeleton. Accurate measurements of radiographs and computer-assisted calculations can provide a three-dimensional motion analysis. Since its introduction 15 years ago, roentgen stereophotogrammetry has found an increasing number of orthopedic applications, which are reviewed here: growth, prosthetic fixation, joint kinematics and stability, fracture stability, and the healing course of spinal fusion and pelvic and tibial osteotomies.