An electrochemically induced tandem reaction has been developed for selective N1-alkylation and C3-halogenation of indoles. This electrochemical difunctionalization strategy circumvents conventional multi-step procedures and efficiently generates synthetically important N-alkyl-3-halo-indoles under more environmentally benign conditions. This reaction can proceed in a simple undivided cell, without the use of any oxidant, base or transition-metal. The excellent atom-economy of this method is highlighted by fully using alkyl halide as both alkylating and halogenating building blocks without atom waste.