A silver-catalyzed phosphorylation/cyclization cascade of N-allyl anilines was developed, allowing direct access to 3-phosphonoalkyl indolines, which were previously obtainable only via tedious procedures under harsh/toxic conditions. The unactivated double bond serves as the radical acceptor, whereas H-phosphonates or -phosphine oxides act as the radical precursor. This protocol features simple operation, broad substrate scope, and great exo selectivity, and a gram-scale synthesis could be readily carried out.