Several 4- or 5-monosubsituted and 4,5-disubstituted 1,2,3-triazole analogues of the anti-HIV-1 lead com pound [1-[2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]thymine]-3'-spiro-5''(4''-amino-1'',2''-oxathiole 2'',2''-dioxide) (TSAO-T) have been prepared and evaluated as inhibitors of HIV-1-induced cytopathicity. These analogues have been prepared by 1,3-diplar cycloaddition of [2,5-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]-3-spiro-5'-(4'-amino- and and 4'-(N-acetylamino)1',2'-oxathiole 2',2'-dioxide) (TSAO) azides to various substituted acetylenes. Several 4- and 5-substituted 1,2,3-triazole-TSAO analogues proved superior to the unsubstituted derivative by 1-2 orders of magnitude. In particular the 5-substituted amido-, (methylamido)-, and (dimethylamido)-1,2,3-triazole derivatives of TSAO were endowed with potent anti-HIV-1 activity (50% effective concentration: 0.056-0.52 mu M). They show a similar resistance spectrum as previously noted for TSAO-T and related derivatives.