The Dementia Signs and Symptoms (DSS) Scale documents non-cognitive signs and symptoms (e.g., delusions, hallucinations, anxiety, depression, mania, and behavioral disturbances) in dementia. Patients, informants, and a clinical examiner rated signs and symptoms over the preceding month. Fifty-six Alzheimer's disease patients were administered the DSS, the BEHAVE-AD, the Cornell Scale for Depression in Dementia, the Young Mania Rating Scales, the Hamilton Depression Scale, the Hamilton Anxiety Scale, and the Psychogeriatric Dependency Rating Scale. DSS subscale scores correlated with corresponding scale scores, confirming construct validity. The DSS subscales were internally consistent (Cronbach's alpha, 0.3 7–0.75) and interrater reliability was high (ICC, 0.92–0.99).