Gastrointestinal stromal tumors (GIST) have mutations of the tyrosine kinase receptor. When they are localized, the treatment of choice is surgical excision, but advanced tumors have a limited response to chemo or radiotherapy. Imatinib (STI571 or Glivec) is a selective inhibitor or tyrosine kinase proteins that has been used successfully in the treatment of advanced GIST. We report four patients (two women) with a metastatic GIST that were treated with Imatinib 400 mg day and followed for 40 months. The disease tumor stabilized in three patients and in one it had an initial reduction and progressed at the end of follow up. Therefore Imatinib can be a therapeutic alternative in patients with metastatic GIST.