Chemistry is an expanding field and presently, medicinal chemistry branch has flourished at a tremendous rate due to active research in this area of field. Alzheimer_s disease (AD) is a progressive, neurodegenerative disorder of the brain among the elderly. It constitutes one of the major health problems in developed countries along with cardiovascular disorders and cancer. The impairment in the cholinergic function which deals with learning, memory, behaviour and emotional responses, is due to rapid hydrolysis of ACh by acetylcholinesterase enzyme (AChE). Thus, AChE inhibition has been documented as a critical target for the effective management of AD by an increase in the availability of ACh in the brain regions. Hence the symptomatic management of patients with AD is based on utilizing acetylcholinesterase inhibitors (AChEIs) such as tacrine, donepezil, rivastigmine, and galanthamine. The present book projects the cholinesterase inhibitors for the management of Alzheimer_s disease.