An efficient, chemoselective and environmentally friendly procedure for the oxidation of sulfides is described. Reactions are carried out using sodium perborate or sodium percarbonate as the oxidant, solvent-free conditions or water as the reaction medium and microwave irradiation or conventional heating as the energy source. A comparative study concerning the effect of the oxidant and reaction conditions on yield and chemoselectivity (sulfoxide vs. sulfone) has been carried out. In the solid phase, the nature of the solid support or catalyst has a more marked influence than the oxidant on the electrophilic and nucleophilic character of the oxidation.