Prevention of drug-related problems is a key issue in the aged. Anticholinergic (ACH) drugs are a biologically plausible and potentially modifiable risk factor for cognitive impairment. Therefore, we intended to evaluate the association between ACH drugs and cognitive impairment. Our study comprised 750 subjects aged 65 years or older. Cognitive impairment was evaluated using Mini-Mental State Examination and Global Deterioration Scale. Patients were classified into ACH-drug users and non-ACH-drug users. Those using ACH drugs (20.1%) were more likely to have cognitive impairment than those using non-ACH drugs (odds ratio, 3.18; 95% confidence interval, 1.93-5.23; P < 0.001); this association remained significant even after adjusting for potential confounding variables (odds ratio, 2.30; 95% confidence interval, 1.19-4.45). Our data suggest that ACH drug intake should be regarded a potentially modifiable risk factor for cognitive impairment in the elderly.