Gastric cancer has a high mortality rate when diagnosed at an advanced stage. Since the primary treatment approach is surgery, accurate staging is crucial for treatment management. F-18 fluorodeoxyglucose positron emission tomography/ computed tomography (PET/CT) is the most commonly used molecular imaging method in Nuclear Medicine, employed for staging, evaluation of treatment response, and detection of recurrent disease in gastric cancer. Recently, fibroblast activation protein inhibitors (FAPI) PET/CT imaging has entered the field, showing superior results in gastric cancer. This review discusses the role of molecular imaging modalities in gastric cancer from various perspectives.