INTRODUCTION: According to the literature, 68Ga-FAPI-04 has receptor specificity for malignant neoplasms with overexpression of the fibroblast activation protein and is used to visualize various types of neoplasms, in particular head and neck cancer, gastrointestinal tract, lung, breast cancer with a high contrast ratio of the tumor to the background, and may possibly become an alternative to 18F-FDG.OBJECTIVE: The results of the first experience of using PET/CT with 68Ga-FAPI-04 in Russia.MATERIALS AND METHODS: A comparative analysis of the results of 68Ga-FAPI-04 and 18F-FDG PET/CTs with an interval of 1–3 days was carried out in 13 patients (four women and nine men) with various oncological diseases, examined from February to December 2021 in Granov Russian Research Center of Radiology and Surgical Technologies.RESULTS: In all 13 patients, it was possible to identify both primary tumors and their metastases with different tracer uptake. 68Ga-FAPI PET/CT compared with 18F-FDG PET/CT revealed more metastatic foci (135 vs 127) predominantly in the liver, peritoneum, mesentery, omentum, and brain due to low background uptake in these organs. In our observation, foci of increased 68Ga-FAPI-04 uptake localized in non-enlarged retroperitoneal lymph nodes in two patients. Also, in two patients with bone metastases from bladder cancer and stomach cancer, one false positive and one false negative result was obtained with 68Ga-FAPI-04.DISCUSSION: The high uptake of 68Ga-FAPI-04 in the tumor makes it a promising tracer for many types of cancer, especially in cases, where conventional 18F-FDG PET/CT faces limitations due to its pharmacokinetics. At the same time, PET/CT with 68Ga-FAPI-04, aimed at visualizing the tumor microenvironment, may have a higher sensitivity in detecting small lesions due to the predominance of stroma in them. 68Ga-FAPI showed better results in detecting both lytic and osteoblastic bone metastases compared to 18F-FDG.CONCLUSION: 68Ga-FAPI is a promising tracer for molecular imaging of most malignant neoplasms and requires further study. 68Ga-FAPI-04 can become an addition or a full-fledged solution when other tracers have limitations.