The antiviral activity of 13(E)-labd-13-ene-8alpha,15-diol (1), isolated from Brachyglottis monroi, was examined against human rhinovirus 2 (HRV2) and 3 (HRV3), and the anticancer activity on human cancer cells (A549 and Hep2). Compound (1) showed strong anti-HRV2 and HRV3 activity with a 50%