The potent anti-HIV-1 activities of L-737,126 (2) and PAS sulfones prompted us to design and test against HIV-1 in acutely infected MT-4 cells a number of novel 1- and 3-benzenesulfonylindoles. Indoles belonging to the 1-benzenesulfonyl series were found poorly or totally inactive. On the contrary, some of the 3-benzenesulfonyl derivatives turned out to be as potent as 2, being endowed with potencies in the low nanomolar concentration range. In particular, (2-methylphenyl)sulfonyl (72) and (3-methylphenyl)sulfonyl (73) derivatives showed EC(50) values of 1 nM. Introduction of two methyl groups at positions 3 and 5 of the phenyl ring of 2 furnished derivatives (80 and 83) which showed very potent and selective anti-HIV-1 activity not only against the wt strain, but also against mutants carrying NNRTI-resistant mutations at positions 103 and 181 of the reverse transcriptase gene.