Objectives: To characterize current practices, barriers, and facilitators to assessing and addressing family caregivers' needs and risks in primary care.; Design: Cross-sectional, national mail-based survey.; Setting: American Medical Association Masterfile database.; Participants: U.S. primary care physicians (N = 106), including general internists (n = 44) and geriatricians (n = 62).; Measurements: Approaches to assessing and addressing family caregivers' needs and risks; barriers and facilitators to conducting caregiver assessments.; Results: Few respondents reported conducting a formal caregiver assessment using a standardized instrument in the past year (10.5%). Informal, unstructured discussions about caregivers' needs and risks were common and encompassed a range of issues, most frequently caregivers' management of patients' safety (41.0%), ability to provide assistance (40.0%), and need for support (40.0%). To address caregiver needs, most respondents endorsed referring patients to services (e.g., adult day care, home care) (69.8%), assessing the appropriateness of the patient's living situation (67.9%), and referring caregivers to community agencies (63.2%). Lack of time was the most frequently cited barrier to assessing caregivers' needs (81.1%). The most commonly endorsed facilitators were access to better referral options (67.0%) and easier referral mechanisms (65.1%). Practice patterns, barriers, and facilitators to caregiver assessment did not differ by physician type.; Conclusions: Primary care physicians use informal, unstructured discussions rather than standardized instruments to assess caregivers' needs and risks. There is heterogeneity in the topics discussed and types of referrals made. Findings indicate the lack of translation of caregiver assessment tools from research to practice.