The objective of the present study is to investigate pollen morphology and taxonomy of some Apiaceae species in Bilecik, Turkey. The study area is restricted to Vezirhan in the south (Bilecik), Pamukova and Geyve in the north (Sakarya), Iznik in the west (Bursa), Golpazari in the south-east (Bilecik) and Tarakli in the east (Sakarya). Apiaceae species were collected from the study area by visiting there in all four seasons. In this study, the pollen morphology of 22 taxa belonging to different genera of the Apiaceae family was investigated for the first time in detail using light microscope and scanning electron microscopy (SEM). The pollen is radially symmetrical, isopolar and tricolporate in all examined species. Pollen grains are perprolate, prolate and subprolate with the polar axis ranging from 17.53 mu m (Non-acetolysed: N) and 18.28 mu m (Acetolysed: A) to 39.71 mu m (N) and 39.72 mu m (A) and the equatorial axis from 11.77 mu m (N) and 12.2 mu m (A) to 23.77 mu m (N) and 23.54 mu m (A). The polar shapes of the studied taxa are triangular. Exine ornamentations of four pollen types have been observed by SEM. Two main groups were revealed in the dendrogram which was constructed by using Average Linkage from the examined data. It was determined that some pollen characteristics of investigated Apiaceae taxa are supporters of the classification of taxa with other taxonomical characteristics. Also, three components of investigated palynological characteristics were identified with principal component analysis. Polar axis (P), equatorial axis (E), the ratio of polar axis to equatorial axis (P/E) (pollen shape) and ornamentation in the polar and equatorial views are determined as the most important palynological characteristics for discrimination of the Apiaceae taxa.