Three different altitudes were selected to study the variability of terpenoid composition from leaves of female plants of Pistacia lentiscus L. throughout the elevation gradient. GC-MS analyses showed that terpenoid contents change with altitude. Forty nine compounds were identified with a high interpopulation variability for low- and midaltitude sites that also exhibited the same major components when data were expressed on dry weight basis. However, Two-Way-ANOVA followed by Tukey's post hoc test showed that monoterpene hydrocarbons increased with elevation, giving values of 21.7, 37.5 and 221.5 µg g⁻¹ dw for low- mid- and highlands, respectively. On the other hand, applying P.C.A. with data expressed in percentage of the chromatogram of the volatile extract led to the identification of three chemotypes associated with altitudinal levels. In highlands (Group I), the major compounds were β-caryophyllene (12%), δ-cadinene (9.3%) and a-pinene (6.3%) while in midlands (Group II), β-caryophyllene (11.5%), δ-cadinene (8.6%) and caryophyllene oxide (6.8%) were the main components. In lowlands (Group III) δ-cadinene (10.9%), cubebol (10.5%) and β-bisabolene (7.7%) were chiefly present. Hence, the involvement of genetic factors, temperature and drought in the chemical polymorphism of P. lentiscus associated with elevation is discussed in this report.