AbstractNew thiols for efficient thiol‐ene polymerization reactions are presented. They do not exhibit any unpleasant odor, are characterized by quite good light‐absorption properties at λ > 300 nm, and generate thiyl radicals upon UV‐light exposure. Due to these interesting properties and contrary to many previously reported methodologies, the present thiol‐acrylate polymerizations can be efficiently carried out without the presence of any additional photoinitiator. The chemical mechanisms are investigated by steady‐state photolysis and electron spion resonance (ESR) experiments. Important parameters can also be extracted from molecular orbital calculations. magnified image