Choliensterase inhibitors are a new class of psychotropic drugs used in the symptomatic treatment of Alzheimer’s disease (AD). Cholinergic deficit is considered to be responsible for the impairment of cognitive functions found in dementia. Inhibition of the acetylcholine inactivating enzyme results in the increased activity of the cholinergic system. There are four drugs registered for the treatment of AD, three of them are available in Poland. The results of clinical studies concerning tacrine, donepezil, rivastigmine and galantamine are presented in this paper. Therapeutic effects of each drug in improving cognitive functions, the level of activities of daily living and behavioural disorders in mild and moderate stages of AD are significant, although modest.