Background: To investigate the use of fused positron emission tomography/computed tomography (PET/CT) compared to contrast-enhanced computed tomography (CECT) in the follow-up of treated gastric malignancies, all data were collected and analyzed retrospectively, enrolling 68 patients (18 females and 50 males) (their age range = 34-73 years). The patients had been referred to a private imaging center for their assessment by PET/CT. Results: Adenocarcinoma was present in 73.5%, lymphoma was present in 23.5%, and malignant carcinoid was found in 3% of cases. All patients had received at least one treatment method including endoscopic/surgical resection, chemotherapy, and radiotherapy. By PET/CT, gastric recurrence/residual was depicted in 30 patients (47.0%) compared 46 patients (67.5%) as detected by CECT, and this was statistically significant (P value = 0.006), nodal metastasis was present in 18 patients (26.5%) compared to 26 patients (38%) as detected by CECT (P value = 0.143), and distant metastasis was present in 18 patients (26.5%) compared to 24 patients (35%) as depicted by CECT (P value = 0.265). Conclusion: PET/CT offered a useful diagnostic modality as compared to CECT for follow-up evaluation of cases with treated gastric malignancies through a precise detection of the gastric lesions but it had rather comparable results in the detection of nodal and distant metastases.