Cholinesterases (ChEs) are key enzymes in the pathogenesis of Alzheimer's disease (AD). A growing body of evidence suggests that plants deliver compounds able to inhibit ChEs (e.g., huperzine A, galanthamine, and physostigmine), thus playing a beneficial therapeutic role in the treatment of AD. Screening for cholinesterase inhibitors (ChEIs) in selected fruits and vegetables showed that extract prepared from bilberry fruit effectively inhibited the activity of acetyl- and butyrylcholinesterase. The purification of ChEIs from bilberry fruit followed by HPLC-UV, FT-IR, NMR, and LC–MS demonstrated that the studied compounds were derivatives of chlorogenic and benzoic acids. These results confirm that bilberry fruit may serve as a useful source of ChEIs, leading to the attenuation of memory deficit caused by AD.