Abstract: Radiopharmaceuticals play a crucial role in nuclear medicine, with the development of radioligands being a key focus in this field. Peptide-based radiopharmaceuticals have shown significant advantages in clinical applications, with the majority of FDA-approved targeting radiopharmaceuticals since 2018 being derived from peptides or peptidomimetics. Bicyclic peptides have emerged as a promising targeting moiety in radioligands, offering improved biophysical properties compared to linear or monocyclic peptide ligands. This article provides an overview of the methods for obtaining bicyclic peptide ligands, as well as highlighting the major clinical and preclinical advancements in bicyclic peptide-based radiopharmaceuticals. The review also discusses the future prospects of bicyclic peptide-based radiopharmaceuticals, offering insights for practitioners in the field of pharmaceutical science and nuclear medicine to keep up with the latest developments in radiopharmaceutical innovation.