A rare accident of a subcutaneous extravasation in the elbow with 4280 MBq 177Lu-PSMA-617 occurred in our clinic. We tried to reduce the damage by warming the elbow for 12 hours, then cooling it, and recommended the patient avoid exercises with the elbow for the next 3 days. We recognized a good resorption of the radionuclide in the scintigraphic imaging in the first 2 days. No pain, burning, or necrosis occurred. The administered therapy afterward showed an adequate decrease in the tumor marker level.