The oil chemical composition was studied in several populations ofJuniperus communis, J. sibirica (J. nana sensuPignatti) andJ. intermediagrowing spontaneously in the northwestern Italian Alps. The oil ofJ. communiswas characterized by high percentages of sabinene (32% to 47%) and low values of α-pinene (9% to 22%), whereasJ. sibiricashowed opposite values (respectively 0.3% to 25% and 9% to 46%). The oil chemical composition ofJ. intermediashowed intermediate values for both sabinene (28%) and α-pinene (20%) when compared to the other two taxa. The data obtained from GC/MS analyses of the oils were used to study the chemotaxonomic characters of the three taxa. Chemometrics included multivariate statistical analyses such as Principal Component Analysis (PCA), Cluster Analysis (CA) and Discriminant Analysis (DA). The results of this investigation indicated that most of the populations considered asJ. intermediashowed a statistically significant different oil composition when compared toJ. communisandJ. sibirica.The taxonomic position ofJ. intermediawas also discussed.