177 Lu is used in peptide receptor radionuclide therapies for the treatment of neuroendocrine tumors. Based on the recent literature, SST2 antagonists are superior to agonists in tumor uptake. The compound OPS201 is the novel somatostatin antagonist showing the highest SST2 affinity. The aim of this study was to measure the in vivo biodistribution and dosimetry of 177 Lu-OPS201 in five anesthetized Danish Landrace pigs as an appropriate substitute for humans to quantitatively assess the absorbed doses for future clinical applications. Results: 177 Lu-OPS201 was obtained with a specific activity ranging from 10 to 17 MBq/?g. Prior to administration, the radiochemical purity was measured as s?>?99.7 % in all cases. After injection, fast clearance of the compound from the blood stream was observed.