A visible-light-promoted method for the selenofunctionalization (and tellurofunctionalization) of alkenes has been developed. This method obviates the prepreparation of moisture-sensitive chalcogen electrophiles. The experimental setup is simple, and superior yields are obtained in the case of selenofunctionalization (up to 99%) while moderate to good yields are obtained in the case of tellurofunctionalization (53-75%). A variety of intra- and intermolecular processes and a short synthesis of the Amaryllidaceae alkaloid (±)-γ-lycorane are demonstrated with this method.