Several 1-(p-R-aryl)-3,3-dimethyltriazenes are anodically oxidized at a Pt electrode in acetonitrile/0.1 M tetrabutylammonium hexafluorophosphate in preparative-scale controlled potential bulk electrolyses. The overall oxidation process produces diazonium ions by cleavage of the N(2)-N(3) bond in the respective primary products, the triazene radical cations, and a subsequent second electron transfer. The diazonium ions react with cathodically formed diacetonitrile (3-aminocrotononitrile) in a paired-type electrolysis to form enamines, which undergo hydrolysis to alpha-arylhydrazono-ketonitriles or an oxidative ring formation to give triazoles. This reaction sequence opens the way to a simple one-pot electrochemical synthesis of these heterocycles from triazenes. Only for R = NO2 a parallel reaction forming nitrobenzene via a diazenyl radical is found.