A short test of mental status (encompassing about 5 minutes) was administered to 93 consecutive neurologic outpatients without dementia, 67 outpatients with Alzheimer-type dementia, and 20 outpatients with dementia of miscellaneous causes. The mean scores for patients with Alzheimer-type dementia were lower than those for the nondemented patients in the total scoring and on all subtests (P less than 0.001). When a total score of 29 or less (maximal attainable score, 38) was used as a screen for dementia, a sensitivity of 92% and a specificity of 91% were reached. For patients older than 60 years of age, a score of 29 or less resulted in a sensitivity of 95% and a specificity of 88%. Thus, in general, this easily administered test distinguishes demented from nondemented patients, but it should not be used as the sole means of diagnosing dementia.