Abstract: C-X-C motif chemokine receptor 4 (CXCR4) is highly expressed on the surface of various tumor cells and plays a crucial role in tumor growth, metastasis, neovascularization, and tumor invasion, has became one of the emerging potential targets for the tumor radionuclide theranostics. C-X-C motif chemokine receptor ligand 12 (CXCL12) is the specific ligand of CXCR4. ⁶⁸Ga-labeled Pentixafor (a CXCL12 analog) can precisely target CXCR4-overexpressing tumors for imaging, which facilitates tumor diagnosis, staging, and formulation of treatment decisions. ¹⁷⁷Lu or ⁹⁰Y-labeled Pentixather (a Pentixafor analog) has been experimentally applied in the internal radiotherapy of CXCR4-overexpressing tumors (such as multiple myeloma and lymphoma, et al) with certain therapeutic effects. The authors summarize the research progress of radionuclide-labeled Pentixafor/Pentixather in CXCR4-targeted theranostics for tumors.