Alzheimer disease (AD), one of the most common diseases presenting dementia, is a progressive neurodegenerative disorder characterized by the depletion of high-affinity nicotinic acetylcholine receptors (nAChRs) and a marked loss of cholinergic neurons. Selective depletion of cholinergic neurons in the basalis of Meynert, decreased activities of choline acetyltransferase, or down-regulation of nAChRs suggest the roles of cholinergic deficits in AD. Donepezil is a therapeutic acetylcholinesterase inhibitor currently being used for the treatment of AD. However, recent studies have also reported off-target effects of donepezil that likely contribute to its therapeutic effects.We investigated the role of donepezil on the processing of amyloid precursor protein (APP) and the involvement of sorting nexin (SNX) 33, a member of the SNX protein family in this study.Donepezil induced an increase in SNX33 expression. The expression of full-length APP in the cell lysate remained unchanged, but the secretion of sAPPα in culture media increased. Donepezil led to a decrease in amyloid β (Aβ) protein levels in a concentration- and time-dependent manner. SNX33 knockdown by target-specific morpholino oligos inhibited the effects of donepezil. Donepezil treatment increased cell membrane surface expression of APP in SNX33 expression-dependent manner. This study shows that donepezil increases SNX33 expression and APP cleavage by α-secretase and reduces the level of Aβ by in primary cortical neurons.