[en] Bone metastases comprise 50-75% cancer complications, in particular ones of breast and prostate. Radionuclide therapy of painful bone metastases has progressed in last decade, but still it is not commonly applied, also due to the clinicians' fears of side effects. This paper overviews the complications of this treatment modality, with particular emphasis to myelotoxicity. It may be concluded that the potential complications should be born in mind by the referring clinician, but it should be stated that radioisotope therapy of bone metastases is a relatively safe modality, safer than external sealed source therapy. (author)