In this paper, we describe a novel uncalibrated active stereo system using coded structured light. Structured-light-based active stereo systems generally consist of a camera and projector that require precise precalibration. Therefore, if we can eliminate the precalibration process from the system, the user can merely place the equipment arbitrarily and directly begin scanning the objects. This will greatly improve both the convenience and practicality of the system. In order to achieve this, we propose an original self-calibration method that can be considered as a camera-to-camera self-calibration method in which one of the cameras is replaced with a projector. We also propose a simultaneous 3D reconstruction method that utilizes multiple captured stereo pairs to increase the accuracy of the 3D estimation. Further, we suggest a simple solution to eliminate the ambiguity of scaling by attaching a laser pointer to the projector, which is important for the practical use of the 3D recons...