Local control and survival of most upper abdominal malignancies are poor. Challenges associated with the safe delivery of tumoricidal doses of radiation therapy to these malignancies include organ motion due to breathing, gastrointestinal filling and peristalsis, and the presence of many normal tissues with a low tolerance to radiation. Intensity-modulated radiation therapy (IMRT) can facilitate normal tissue sparing and dose escalation to these tumors, which has the potential to reduce toxicity and improve local control. Planning studies have demonstrated the potential for dose escalation with IMRT. However, degradation of upper abdominal IMRT plans in the presence of organ motion has also been demonstrated. Thus, organ motion reduction and image guidance strategies should be implemented in conjunction with IMRT. Clinical experience with dose-escalated IMRT is limited, and IMRT should continue to be studied in clinical trials before it is routinely used for upper abdominal malignancies.