A simple and directed synthetic strategy starting from 2-alkynylarylketones was developed for the construction of various indenones under metal-free and water-assisted conditions. This intramolecular cyclization reaction could well tolerate a wide range of functional groups, and the corresponding functionalized indenones were obtained in moderate to excellent yields (up to 94%). In addition, the possible mechanism of this reaction may involve isobenzofuranium intermediates.