The anti-HIV-1 activity of aromatic herbs in Labiatae was evaluated in vitro. Forty five extract from among 51 samples obtained from 46 herb species showed significant inhibitory effects against HIV-1 induced cytopathogenicity in MT-4 cells. In particular, the aqueous extracts of Melissa officinalis, a family of Mentha x piperita "grapefruit mint," Mentha x piperita var. crispa, Ocimum basilicum cv "cinnamon," Perilla frutescens var. crispa f. viridis, Prunella vulgaris subsp. asiatica and Satureja montana showed potent anti-HIV-1 activity (with an ED of 16 microg/ml). The active components in the extract samples were found to be water-soluble polar substances, not nonpolar compounds such as essential oils. In addition, these aqueous extracts inhibited giant cell formation in co-culture of Molt-4 cells with and without HIV-1 infection and showed inhibitory activity against HIV-1 reverse transcriptase.