This chapter presents a general analysis of the transannulations of 1-sulfonyl-1,2,3-triazoles with cyclic substrates with an emphasis on advances in recent years in this field. These transannulation reactions can occur either with the retention of the ring of the substrate, providing fused heterocyclic systems, or its opening, which generates a variety of unique heterocycles of various sizes and constituents. Future perspectives in this field are also discussed.