Abstract: The results of studies performed at the Khlopin Radium Institute in cooperation with other institutions from Russia and other countries, and also published data in the field of chemistry of higher technetium carbonyl compounds are summarized in the context of problems of nuclear medicine. Chemical problems that arise on the way of using higher technetium carbonyls in nuclear medicine and are associated with the synthesis conditions and reactivity of these complexes, and also the ways to solve these problems are analyzed. The major problems are the need for using high pressures in synthesis, the impossibility of direct replacement of halogen in pentacarbonyl halides (products directly obtained from pertechnetate ion) by other monodentate ligands, limited resistance of many higher technetium carbonyls to decarbonylation, and susceptibility of higher technetium carbonyls to nucleophilic reactions (including hydrolysis in alkaline media). The latter problem seems to be the most critical. The scientific outcome of the studies is outlined, and comparison with rhenium analogs is made. The complex [^99mTcI(CO)₅] shows promise for lung imaging; assumptions concerning the mechanism of its lung uptake are formulated.