In this study, mass fractions of paclitaxel, cephalomannine, 10-DAB III and baccatin III in hazelnut were measured with new and validated LC-MS/MS method. Green outer nut husk and nutshell of Turkish hazelnut (Corylus colurna L.) were collected from Duzce, Trabzon, Adapazari and Samsun at several altitudes during August and September in 2014. The target analytes were prepared using solid-liquid extraction and analysed by LC-MS/MS. High amount of baccatin III, used for synthesizing semi-synthetic paclitaxel, was found in the nutshells collected at 250-500 m altitude in Cumayeri district of Duzce. In the husk samples from Vakfikebir district of Trabzon, the highest amount of baccatin III was obtained. The mass fractions of baccatin III in nutshell and husks were between 164.38-1020.85 mu gkg-1 and 166.12-923.64 mu gkg-1, respectively.