A fast and efficient process for the production of the PET radionuclide73Se was developed using75Se as a surrogate.75Se was separated from proton irradiated arsenic trioxide by reaction with 2,3-diaminonaphthalene to 4,5-[75Se]benzopiazelenol. This compound was purified using SPE column chromatography and subsequently decomposed with hydrogen peroxide. For further chemical conversions [75Se]selenite was reduced to elemental [75Se]selenium by either using thiosulfate or sulfur dioxide. The recovery yield of75Se from the target amounted to 43%. The utility of the isolated75Se for radiosyntheses was demonstrated by the successful preparation of [75Se]selenomethionine. The methodology developed using75Se was successfully transformed to73Se.