Reactions of morpholine, piperidine and piperazine with Os(VIII) catalyzed hexacyanoferrate(III) in alkaline media to produce the corresponding lactam have been studied at constant temperature and ionic strength.. The reactions followed first order kinetics with respect to [amine] and [Os(VIII)] but were independent of [Fe(CN)63-] and [OH-]. The effects of introduced electrolytes, potassium hexacyanoferrate(II), relative permitivity and temperature have also been studied. A mechanism accounting for these results has been proposed.