Galanthamine, used as a drug for the treatment of Alzheimer's disease and lycorine possessing important biological properties, are widely distributed alkaloids in the members of Amaryllidaceae family. In the present study, the contents of these alkaloids have been quantitatively determined by high-performance liquid chromatography (HPLC) coupled with diode array detector (DAD) in the aerial parts and bulbs of Galanthus woronowii Losinsk. collected from different localities in Northeastern Turkey. A simple extraction method utilizing columns pre-packed with diatomaceous earth (Extrelut (R)) was used. Chromatographic separation was achieved using an isocratic system with a mobile phase of trifluoroacetic acid-water-acetonitrile (0.01:90:10) applied at a flow rate of 1 mL min(-1). Validation studies were also carried out to show that the method is specific, accurate, and precise. In the tested specimens, the lycorine content ranged between 0.008 and 0.364% whereas the galanthamine content was found to be between 0.003 and 0.506%.