An efficient cascade bicyclization strategy for the construction of γ-lactam containing 3,3-disubstituted oxindole derivatives under silver catalysis is described. The method enables the sequential assembly of both unactivated and activated double bonds in N-phenyl-4-pentenamide and N-methyl-N-phenylacrylamide in one pot through a cascade intramolecular cyclization/radical addition/cyclization process. Two N-heterocycles with one C–N bond and two C–C bonds were formed simultaneously. Moreover, the approach is general and exhibits wide functional group compatibility, providing access to a variety of bicyclic N-heterocycle products.