The sapwood and heartwood of lodgepole pine (Pinus contorta) and knobcone pine (P. attenuata) have been examined for monoterpenes, fatty and resin acids. While eleven monoterpenes were identified as common to both species, the principal difference in the monoterpenes is in their major components, namely β-phellandrene (71 per cent) in lodgepole pine and α-pinene (72 per cent) in knobcone pine. Four fatty acids and eight resin acids were identified as common to both species. © 1969.