Forty constituents (accounting for 99.96-94.96 wt% of total volatile constituents) have been identified in the oils of twelve lemon cultivars grown in Sardinia. A statistical analysis of data was performed using Principal Component Analysis (PCA) method; through this analysis most lemon cultivars could be clustered into two groups. The nucellar cv.Santa Teresa(165 and ICAS 146) andInternodato, which possess different essential oil compositions, could not be clustered into either of the two groups, in fact they were even differentiated from one another.