AbstractHeartwood samples from three species of Juniperus (i.e., J. virginiana, J. occidentalis, and J. ashei) were extracted with hexane, ethanol, and methanol. The hexane and ethanol extracts were tested for antifungal activity against four species of wood-rot fungi (i.e, Gloeophyllum trabeum, Postia placenta, Trametes versicolor,and Irpex lacteus). Ashe juniper (AJ) gave the highest extract yields (6.60 to 11.27%), followed by Eastern red cedar (ERC) (4.78 to 9.56%), and then Western juniper (WJ) (4.26 to 7.32%). WJ contained the highest level of cedrol (over 60%), while AJ contained the highest level of thujopsene (over 30%). Methanol and ethanol gave the highest extract yields as well as slightly higher percentages of cedrol and widdrol. The juniper extracts were more effective against white-rot fungi than brown-rot fungi. The ethanol extracts had higher antifungal activity than the hexane extracts. The AJ extracts had the greatest bioactivity against the wood-rot fungi.