Research was aimed at the determination of the fatty acid and volatile composition of oils made from Ayvalk olives grown in Turkey and the effects played by maturity and altitude on composition. Samples were obtained from five orchards located at 25, 74, 132, 202 and 250m above sea level in Edremit (Balkesir, Turkey). Olive samples were harvested at three maturity levels (green, semi-black and black) in 2007 and 2008 to extract the oil. E-2-hexenal was found to be the main volatile compound in all samples and its concentration decreased as maturity progressed. Hexanal and E-1-pentene-3-one were also at high levels in all samples. Levels of all aroma compounds, except E-2-hexenol and hexylacetate, decreased with the degree of ripeness. Altitude plays an evident but less intense effect on the volatile composition. Copyright (c) 2015 John Wiley & Sons, Ltd.