3'-Deoxy-3'-(1, 2, 3-triazol-1-yl)thymidines (5a, 6a, 8a, 11a, and 12a) and 2', 3'-dideoxy-3'-(1, 2, 3-triazol-1-yl)uridines (5a, 6b, 8b, 11b, and 12b) were synthesized as cyclic analogues of 3'-azido-3'-deoxythymidine (AZT) and 3'-azido-2', 3'-dideoxyuridine (CS-87) by the cyclization of 5'-trityl derivatives (1a, b) of AZT and CS-87 using α-ketophosphorus ylides and with acetylenic compounds followed by deprotection of the 5'-trityl group. It was hypothesized that the triazole nitrogen atoms could mimic and distorted azido group. However, no significant activity against human immunodeficiency virus type 1 (HIV-1) was observed with any of these compounds. 5'-Triphosphates (17a and 18a, b), prepared from 5a and 6a, b, were inactive against HIV-1 and Rausher murine leukemia virus (RLV) reverse transcriptases.