Purpose <p>To evaluate the diagnostic value of [⁶⁸&#xa0;Ga]FAPI-04 PET/CT for detecting recurrence and metastasis after surgery in differential thyroid carcinoma (DTC) and to compare it with [¹⁸F]FDG PET/CT.</p> Methods <p>This retrospective study included patients with recurrence and metastasis who underwent both [⁶⁸&#xa0;Ga]FAPI-04 PET/CT and [¹⁸F]FDG PET/CT after DTC surgery. We analyzed the detection rates and uptake values of [⁶⁸&#xa0;Ga]FAPI-04 PET/CT, conducted receiver operating characteristic curve (ROC) analysis for maximum standardized uptake value (SUVmax), and assessed correlations with clinical indicators. Additionally, We compared the differences between the two imaging semi-quantitative parameters, as well as the differences in sensitivity and specificity.</p> Results <p>A total of 65 patients who underwent [⁶⁸&#xa0;Ga]FAPI-04 PET/CT had 231 lesions, only a small subset (n = 10) underwent both [⁶⁸&#xa0;Ga]FAPI PET/CT and [¹⁸F]FDG PET/CT (100 lesions). The results of 36 patients were confirmed by histopathological findings, while the results of 29 patients were determined based on clinical and imaging follow-up results. The sensitivity of [⁶⁸&#xa0;Ga]FAPI-04 PET/CT for lymph nodes, lungs, and bones lesions were 0.948, 0.943, and 0.963, with specificities of 0.75, 0.882, and 0.5, respectively. The highest uptake was observed in the liver lesions, followed by local recurrence, lymph nodes, bones, pleura, and lungs lesions. ROC analysis indicated meaningful thresholds for lymph node and lung lesions. SUVmax and TBR were weakly positively correlated with lesion diameter. For SUVmax and TBR, [⁶⁸&#xa0;Ga]FAPI-04 PET/CT values were lower than those of [¹⁸F]FDG PET/CT. There was no significant difference in sensitivity and specificity between the two imaging methods. A positive correlation was observed between SUVmax and TBR in both imaging techniques. There was no significant difference between the levels of thyroglobulin (Tg), thyroglobulin antibody (Tg-Ab) and the uptake of [⁶⁸&#xa0;Ga]FAPI-04.</p> Conclusion <p>[⁶⁸&#xa0;Ga]FAPI-04 PET/CT shows good detection capabilities for recurrence and metastasis in postoperative DTC patients. In addition, the overall accuracy of [⁶⁸&#xa0;Ga]FAPI PET/CT in detecting lymph node, lung and pleural lesions is higher than that of [¹⁸F]FDG PET/CT, while the overall accuracy of [¹⁸F]FDG PET/CT in detecting bone lesions is higher than that of [⁶⁸&#xa0;Ga]FAPI PET/CT.</p>