In this paper the Coronary Artery Tracking competition, which was part of the workshop: "3D Segmentation in the Clinic: A Grand Challenge II" is described. This workshopwas held during the 2008 Medical Image Computing and Computer Assisted Intervention (MICCAI) conference. An introduction is given to underline the importance of (semi-)automatic coronary artery centerline extraction methods and the advantages of an online framework facilitating a fair comparison of these methods. Furthermore, information is provided about the set-up of the workshop, the evaluation measures used and the online framework. Results for the algorithms, submitted by both industrial and academic research institutes, are presented as well.