Estimates of the reported prevalence of visual hallucinations in the elderly vary from study to study. The aim of the present investigation was to re-evaluate the prevalence of visual hallucinations in elderly psychiatric outpatients and to examine pertinent risk factors. One hundred and twenty-two elderly (> or =60 years old) consecutive outpatients at our university hospital were investigated with a questionnaire regarding visual hallucinations and the Mini-Mental State Examination. Twelve of 122 (10%) patients suffered from visual hallucinations. Although advanced age, lower MMSE scores and dementia were significantly associated with the presence of visual hallucinations, logistic regression analysis revealed that only advanced age showed a tendency to predict the presence of visual hallucinations. In 53 patients with dementia examined separately, only advanced age was significantly associated with visual hallucinations. The present findings suggest that the prevalence of visual hallucinations in the elderly is about 10% and that aging is an important risk factor in the development of visual hallucinations in dementia. Further studies are required in order to investigate the contribution of age-related factors such as lowering visual acuity, bereavement and loneliness to the presence of visual hallucinations.