The volatile oil of the aerial part of Lactuca serriola L. was obtained by the hydro-distillation method for 3 hours with the Clevenger-type apparatus. The chemical composition of oils was determined by GC-MS analyses. Forty-three constituents were identified in oil (84.3%). Heneicosane (8.4%), (E)-β-ionone (6.5%), hexadecanoic acid (6.4%), hexahydrofarnesyl acetone (6.3%), tricosane (5.5%), heptacosane (5.5%), phytol (5.0%) and pentacosane (4.1%) were determined as main ingredients in the oil. The oil has saturated n-alkane derivatives as a dominant group. To the best of our knowledge, this is the first report on the chemical composition of volatile of L. serriola from Turkey.