THE friction of rubber on both smooth and rough surfaces has been shown to be related to its viscoelastic properties1. The friction of rubber on ice has not received much attention2–4 and no attempt has been made previously to determine whether the process differs substantially from that on other smooth surfaces. We describe here the effect of speed and temperature on the friction coefficient of unfilled rubber vulcanizates, sliding on smooth ice and compare these results with those obtained on other surfaces under similar conditions1,5.