[en] ^99mTc used for labelling different pharmaceuticals is the most important radionuclide in nuclear medicine practice, and probably will continue to play this important role for the foreseeable future. ^99mTc is the short lived daughter product of the parent ⁹⁹Mo, which is mainly produced by the nuclear fission of ²³⁵U. Recognizing the importance of the waste management issue associated with ⁹⁹Mo production the IAEA initiated preparation of this report to provide Member States and existing and potential producers of ⁹⁹Mo with practical approaches and the available information on the subject. Waste management in the context of this report encompasses all waste-related aspects, for example, handling, treatment, conditioning, storage, transport, and disposal. The document is organized in several chapters giving the following information: short description of the basic nuclear and physical properties of ⁹⁹Mo and ^99mTc; an overview of past, present and possible future production methods; characteristics of the various waste streams produced in the aforementioned processes; description of the necessary waste management practices needed to handle the relevant waste streams in a responsible and internationally-accepted manner; conclusion and recommendations