The dried rhizomes of Indonesian ginger, Zingiber officinale, were investigated for antirhinoviral activity in the plaque reduction test. Fractionation by solvent extraction, solvent partition, and repeated chromatography guided by bioassay, allowed the isolation of several sesquiterpenes with antirhinoviral activity. The most active of these was beta-sesquiphellandrene [2] with an IC50 of 0.44 microM vs. rhinovirus IB in vitro.