Solitary fibrous tumors are fibroblast tumors that occur mainly in the peritoneum, extremities, and pleura. Here, we report the MRI, FDG PET/CT, and FAPI PET/CT findings of a rare prostate solitary fibrous tumor. A 57-year-old man was pathologically diagnosed with a solitary fibrous tumor. To detect any systemic metastases or other primary lesions, the patient underwent FDG PET/CT and FAPI PET/CT examination sequentially. Mild FDG uptake was observed in the primary prostatic lesion, but there was a significant uptake of FAPI in the prostate. This case highlighted that FAPI PET/CT may outperform FDG PET/CT in identifying solitary fibrous tumors.