A radiometric method based on the redox substoichiometry has been developed for the determination of tellurium. The oxidation of tellurium(IV) to tellurium(VI) with potassium dichromate was employed as the substoichiometric reaction, followed by TBP (tributyl phosphate) extraction of the unreacted tellurium(IV) as the substoichiometric isolation. The oxidation of tellurium(IV) with dichromate under the substoichiometric conditions was incomplete. The chemical yield of tellurium(VI) produced by the oxidation of tellurium(IV) with dichromate was 83%. It was found that a tellurium content of 50 to 160 g could be determined with an accuracy of ±1.3% by means of the comparison method.