Radionuclide therapy continues to gain in importance thanks to promising clinical results. It is a suitable treatment option for many patients and is increasingly establishing itself as a key pillar in the treatment of metastatic castration-resistant prostate cancer (mCRPC). This article summarizes the current role of radionuclide therapies in the treatment of mCRPC and provides insights into recent developments. Presentation of key study results, current approval labels and ongoing clinical trials. Significant prolongation of survival through treatment with lutetium-177-PSMA-617 and radium-223-dichloride has led to approval of both substances in late-stage mCRPC. Further study results on the effectiveness of lutetium-PSMA in earlier stages and on the use of the alpha emitter actinium-225 are expected.