The 20th ACM SIGSPATIAL Conference on Advances in Geographic Information Systems (GIS) was held in November of 2012. In conjunction with this conference, we organized the conference’s first competition, called the SIGSPATIAL GIS Cup 2012. The subject of the competition was map matching, which is the problem of correctly matching a sequence of noisy GPS points to roads. We describe the details of the contest, the results of the competition, and the lessons we learned in running a contest like this.