Purpose <p>A growing number of studies are focusing on the possibilities of [⁶⁸Ga]Ga-FAPI PET/CT in diagnosis of tumors of various localizations. It has been established that [⁶⁸Ga]Ga-FAPI PET/CT has high diagnostic efficiency in head and neck tumors, lung cancer, breast cancer, abdominal tumors, as well as in sarcomas, both in the primary tumor detection and in search of distant metastases. The aim of this study is to evaluate the performance of [⁶⁸Ga]Ga-FAPI PET/CT for the diagnosis of bone and soft tissue sarcoma, compared with [¹⁸F]FDG PET/CT.</p> Methods <p>We screened all patients (pts) who underwent dual-tracer [⁶⁸Ga]Ga-FAPI and [¹⁸F]FDG PET/CT from 2022–2025. Both examinations were performed within 1&#xa0;week for assessment of primary tumor, local relapse or distant metastasis. Positive lesions on PET/CT images were verified by biopsy, 3–12-month follow-up and MRI/contrast-enhanced CT. A paired t test was used to compare the semiquantitative values (SUV_max and TBR) of [¹⁸F]FDG and [⁶⁸Ga]Ga-FAPI PET/CT in tumor lesions. Primary tumors in patients were detected by morphological verification. To evaluate metastases in other organs and lymph nodes, we used histological data, MRI or dynamic follow-up. These results were used to calculate the diagnostic efficiency (sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Ac)) for each modality on a per-region basis.</p> Results <p>Twenty-six patients (15 women and 11 men; average age – 44&#xa0;years) representing 17 sarcoma subtypes were included in the final analysis. A total of 128 tumor lesions were identified. Compared with [¹⁸F]FDG, [⁶⁸Ga]Ga-FAPI demonstrated significantly higher uptake in dedifferentiated liposarcoma, malignant solitary fibrous tumors, and fibrosarcoma (mean SUV_max: 29.26 ± 16.90 vs. 5.93 ± 5.60; p &lt; 0.001). Conversely, [¹⁸F]FDG demonstrated higher uptake intensity in synovial sarcoma, pleomorphic sarcoma, leiomyosarcoma, and intimal sarcoma (mean SUV_max: 10.77 ± 4.64 vs. 5.24 ± 2.24; p = 0.0089). On a per-region basis, [⁶⁸Ga]Ga-FAPI yielded a sensitivity of 68.52%, specificity of 66.67%, and accuracy of 68.22%, compared with 71.57%, 34.62%, and 64.06%, respectively, for [¹⁸F]FDG.</p> Conclusion <p>Compared with [¹⁸F]FDG, [⁶⁸Ga]Ga-FAPI PET/CT demonstrates superior diagnostic capability for specific subtypes, including dedifferentiated liposarcoma, malignant solitary fibrous tumors, and fibrosarcoma. However, for other subtypes, [⁶⁸Ga]Ga-FAPI provides comparable or inferior diagnostic yield. These findings suggest that radiotracer selection should be tailored to specific histological subtypes to optimize diagnostic accuracy in sarcoma management.</p>