Alzheimer's disease is an advanced dementia. In this disease, little by little the brain loses most of its functions. Pain is a prevalent complaint. It seems easing the pain had the better recovery to antipsychotic drug in controlling agitation in dementia patients. Donepezil is a drug that is used to treat Alzheimer's disease. This brief report describes an 83-year-old woman with Alzheimer's disease who experienced boredom and changes in attitude for about 1 year and complained about general pain in her extremity. Starting donepezil controlled the patient's symptoms. As soon as the treatment started, all pain was dramatically eliminated and her behavior improved. Donepezil may be effective in controlling the pain and improve the outcome of these patients.