Xylem oleoresin of slash pine (Pinus elliottii Engelm.) was obtained from ortets and ramets of 10 clones and half-sibs of 4 families. Samples were collected at 4-foot intervals from the base to the top of the tree. Monoterpene yields (microliters per gram oleoresin) and composition (percent of total monoterpene) were estimated by gas-liquid chromatography. When all three monoterpenes were present, α-pinene decreased markedly from base to crown, -phellandrene increased, and -pinene remained relatively constant. With two components present, α-pinene remained constant or slightly increased while -pinene remained constant or slightly decreased from base to crown. Results were similar for both composition and yield. Samples from the bottom of the crown gave the most consistent results among clonal and family members of varying size. Therefore, sampling slash pine at the base of the crown rather than at an arbitrarily fixed height should be considered. Forest Sci. 22:185-191.