This technical note describes the development and evaluation of a low-cost motion capture and analysis system (SOMCAM3D). From diverse video sequences obtained by commercial cameras, synchronized by a certain event, and calibrated from a calibration process, the system is able to reconstruct three-dimensional positions in a reference system defined by the calibration process. From these positions, a wide variety of kinematic variables could be calculated. This system aims to analyze movement in applications of gait analysis, sports, animals, ergonomics, robotics, etc. It is designed to work with low-cost equipment (commercial cameras, computers, etc.). Also it allows us to work in 2D, outdoors, and without marks. Finally, this technical note includes a study of how precise and accurate this system is.