A metal-free radical 1,2-difunctionalization of activated alkenes with various silanes and tert-butyl nitrite is reported. The radical cascade occurs by light-promoted homolytic O-NO bond cleavage of tert-butyl nitrite and subsequent hydrogen atom abstraction by the alkoxyl radical from the silane. Silyl radical addition to the alkene and highly selective cross-coupling of the NO radical with the Si-adduct C-radical provide the silyl-oximation product in moderate to good yields. The reaction features good functional group tolerance and is easily scaled up.