The processes of electrochemical phosphorylation of alkenes were investigated. It was found that anodically generated radical-cations of trialkyl phosphites, dialkyl trimethylsilyl phosphites, mono- and diamidophosphites were added to olefin molecules to give unsaturated alkenephosphonates. The anodic oxidation of tetraalkyl pyrophosphites proceeds with disintegration of initial radical-cations and leads to mixture alkane- and alkenephosphonates. Greater amounts of alkanephosphonates were formed during anodic oxidation of sodium (or lithium) dialkyl phosphites in the presence of alkenes.