The mangosteen international standard for export requires fruit free from scar. This was the most constraining issue for the Indonesian export of mangosteen. Thrips are pests which cause scars on mangosteen fruits. Hence, there is an inevitable need to control the thrips population. This research was aimed at identifying the thrips pest that causes scars on the mangosteen fruit. This project was also aimed at studying the effects of using yellow fluorescent sticky trap (YST), and the combination treatment: YST and intensive orchard care (YST+IOC) on the percentage and intensity of fruit scars caused by thrips. The research was conducted at a farm with a polycultured mangosteen orchard in Lima Puluh Kota, West Sumatra, Indonesia. It was conducted during the two fruit seasons from September 2006 to February 2007, and from October 2007 to February 2008. The results showed that there were two species of thrips pests that are associated with the mangosteen: Scirtothrips dorsalis (Hood) and Selenothrips rubrocintus Giard. All of the treatments gave significant differences in decreasing the percentage and intensity of scars. These differences were significantly different compared to the control group in the first year as well as in second year. The combined treatment of YST+IOC proved to have the best results in reducing the percentage (41.19% and 43.96%) and intensity of scars (32.14% and 15.81%) in the first year as well as in the second year, respectively.