Facile synthesis of fused 1,2,3-triazoles by a proline-catalyzedreaction of an azido aldehyde and a nitroalkane is elaborated. The present tandem protocol proceeds via an organocatalytic Knoevenagelcondensation of the azido aldehyde and nitroalkane followed by intramolecular azide–nitroalkene cycloaddition. The functionalized bicyclic triazole is obtained by elimination of HNO2 from the cycloadduct