Forty-five authentic samples of Greek virgin olive oils, collected from various locations over two seasons, were analysed for fatty acid composition by GLC and for triglyceride composition by HPLC. The data obtained were analysed statistically using Principal Component Analysis. The olive oils could be separated into distinct groups using either the fatty acid or triglyceride data, although the latter provided a higher level of discrimination. It was concluded that the method showed considerable potential for both the characterisation of olive oils and the detection of adulteration.