Chloroform:methanol extracts of the bulbs of five Amaryllidaceae plants, namely Galanthus elwesii Hooker fil., G. ikariae L., Narcissus tazetta subsp. tazetta L., Leucojum aestivum L., and Pancratium maritimum L. growing in Turkey, were evaluated for their anticholinesterase activity by the Ellman method in comparison with galanthamine as the standard drug. Bioactivity-directed fractionation and isolation studies carried out on G. ikariae and N. tazetta subsp. tazetta extracts afforded eight Amaryllidaceae-type alkaloids in total. We found that the activity of both plant extracts was due to the synergistic interaction of the alkaloids isolated.