The presence of c-kit mutation is an independent poor prognostic factor for relapse in addition to large size (> 5 cm) and high mitotic rate (> 5/50 high power field [HPF]) in localized gastrointestinal stromal tumor (GIST) patients who underwent complete surgical resection. In addition, the localized GIST which had exon 11 c-kit mutation and features of high-risk for relapse according to National Institute of Health (NIH) consensus guideline (tumor size > 10 cm or mitotic count > 10/50 HPF) also have high-risk of relapse. Until recently, there has been no effective therapy for advanced, unresectable GISTs. However, a new agent, imatinib mesylate, has shown promise in the metastatic setting, and c-kit exon 11 mutation is the strongest prognostic factor for better response and survival. It is reasonable to try imatinib in an earlier and minimal residual status especially for patients at higher risk of relapse and a higher probability of response to imatinib.