The authors sought to evaluate the incidence and correlates of anxiety in early-onset Alzheimer's disease (EOAD) versus the more typical late-onset AD (LOAD). A group of 23 EOAD and 22 LOAD patients were compared by the Neuropsychiatric Inventory Anxiety subscale. Demographic and disease-related relationships with anxiety were evaluated, as well as types of anxiety symptoms that were endorsed. EOAD patients had significantly more anxiety symptoms than LOAD patients. Among those with EOAD, anxiety was associated with male gender, higher Mini-Mental State Exam score, and separation from caregivers. Among LOAD patients, anxiety was associated with psychotic and activating psychiatric symptoms. These results have implications for the management and alleviation of anxiety in AD.