Objective: To describe development, validity, and application of the Problem Behavior Inventory (PBI), a tool to assess dementia-related problem behaviors (DRPBs) in community-based populations. Data Sources and Study Setting: Demographic, contact, and disease-specific data were extracted from client files from a Medicaid-funded home and community-based services program. Primary caregivers completed standard surveys relating to the care recipients' memory, mood, and behaviors. The client (care recipient) completed the Mini-Mental Status Exam (MMSE). Study Design: Cognitively impaired clients, enrolled in the Community Care Services Program (CCSP) during a reference month, and their primary caregivers, were identified by CCSP case managers for participation in the study. Primary caregivers completed the Revised Memory and Behavior Problem Checklist (RMBPC). Clients screening positive for the presence of DRPBs based on caregiver responses to the RMBPC were then assessed using the Problem Behavior Inventory (PBI). Principle Findings: Within the CCSP sample, the most prevalent behavior was appearing sad or depressed (67%), while the most frequent behavior was seeking attention, occurring at least daily in 58% of the group. The most bothersome behaviors were being sexually inappropriate, wandering, and misbehaving in public. Examination by behavior category (physical, verbal, mood, etc.) revealed a strong relationship between level of bother and behavior frequency. Frequency of verbal behaviors was positively related to MMSE scores, whereas frequency of ADL-related behaviors was inversely related to MMSE scores. Bother scores were not associated with MMSE scores. Conclusions: This study documents that the PBI is a valid, useful, and feasible tool for assessing DRPBs in community populations. Case managers using the PBI can determine specific problem behavior areas among client populations and for individual clients and institute client-specific interventions to address each issue.