In the diagnosis, treatment, and care of dementia patients in the senile stage, comprehensive evaluation of ability in daily life and mental function is needed. Using a simple behavioral rating scale for the mental states (NM scale) and activities of daily living (N-ADL) of the elderly, we evaluated 250 elderly subjects. According to the NM scale, the scores for subjects in whom the severity was clinically diagnosed were as follows: normal, 50–48; borderline, 47–43; mild dementia, 42–31; moderate dementia, 30–17; and severe dementia, 16–0. Screening for dementia and determining its severity were readily accomplished using the NM scale, and basic activities in the daily life of the elderly could be evaluated effectively using the N-ADL. There was a significant correlation (r=0.863) between the Hasegawa dementia scale and the NM scale (p<0.001), a significant correlation (r=−0.947) between intellectual function scores of the GBS scale and the NM scale, and a significant correlation (r=0.944) between motor function score of the GBS scale and the N-ADL score. Evaluations of daily life activities can be made not only by psychiatrists and clinical psychologists, but by nonspecialists as well, because they are based on data obtained by observation of daily life behaviors; thus, assessment is appropriate both in clinical settings and in places of living.