The electrochemical oxidation of three cyclic polysilane derivatives, namely [(n-Pr)(2)Si](4) (I), (Me(2)Si)(6) (II) and (Et(2)Si)(7) (III), in dichloromethane or methanol, in the presence of ClO4-, HSO4- or AcO- salts, on graphite or Pt anodes, provides cyclic and linear siloxanes as major products, stemming from oxygen insertion and ring-opening processes respectively. The effects of ring-size, electrolyte, solvent, atmosphere and anode material are discussed.