Summary of main observation and conclusion The importance of CF3‐containing molecules in pharmaceuticals, agrochemicals and materials intrigues the intense interest in synthetic methodology of these compounds. With a purpose to enrich trifluoromethylation methodology, we carefully examined the substrate scope of hydroxytrifluoromethylation of alkenes using iodotrifluoromethane, and the reaction provided β‐trifluoromethyl alcohols in good yields under extremely mild conditions without catalysts. We found that our reaction can be applied to not only styrenes but also various aliphatic alkenes with excellent selectivity; no ketone was detected in most of our cases. Another feature of our discovery is “simple”. The reaction was carried out in air, irradiated by visible light, at room temperature and most importantly no catalyst was needed. A solution of CF3I in DMSO was used as the facile trifluoromethylating reagent, which simplified the utilization of gaseous CF3I. Based on 19F NMR spectroscopy, we observed a halogen bond between CF3I and tertiary amine in this reaction. The interaction may promote single electron transfer by the visible light irradiation. The reaction can be applied to not only styrenes but also various aliphatic alkenes with excellent selectivity. We propose a halogen bond interation promotes a single electron transfer under the visble light irradiation. No catalyst was needed. A solution of CF3I in DMSO was used as the facile trifluoromethylating reagent.