The ¹⁸F 2-fluoro-2-deoxyglucose (FDG) PET/CT scan is an imaging modality used in the management of patients with various types of malignancies. ¹⁸F-FDG PET/CT has demonstrated significant efficacy in the staging and detection of metastatic disease in malignancies of the gastrointestinal tract. The assessment of the metabolic response to chemotherapy and improvements of overall survivals in malignancies of esophagus and stomach has been demonstrated in several studies. This review focuses on the role of ¹⁸F-FDG PET/CT scan in staging, metastasis, predict of recurrence and assessment of metabolic response in malignancies of the upper gastrointestinal tract.