This paper 1 describes a method for tracking regions in image sequences. Regions segmented from each frame by a motion segmentation technique are matched by using a relaxation procedure. Matching is based on measuring the similarity of the regions from the current frame and a list of regions corresponding to objects. A Kalman filter is used in order to estimate motion parameters. This filter uses a kinematic model, which considers varying acceleration. This assumption allows the system to model the movement when objects are approaching to the camera to the camera. The tracking method presented here has been successfully applied to traffic monitoring tasks, where it connects to other two-computer vision based modules: motion segmentation and temporal integration.