OBJECTIVES: To determine primary care physicians' awareness of, and screening practices for, alcohol use disorders (AUDs) among older patients. DESIGN: Cross-sectional telephone survey of a national sample of primary care physicians. PARTICIPANTS: Physicians randomly sampled from the Masterfile database of the American Medical Association and stratified by specialty as family practice physicians, internal medicine physicians, and either family practice or internal medicine physicians with geriatric certification. MAIN RESULTS: A total of 171 physicians were contacted: 155 (91%) agreed to participate, and responses were analyzed from 150 (50 family practice, 50 internal medicine. 50 with geriatric certification). The median prevalence estimate of AUDs among older patients was 5% for each group of physicians. In contrast to published prevalence rates of AUDs ranging from 5% to 23%, 38% of physicians reported prevalence estimates of less than 5%, and 5% cited estimates of at least 25%. Compared with the other groups, the physicians with geriatric certification were more likely to report no regular screening (42% vs 20% for family practice vs 18% for internal medicine, p = .01), while younger (<40 years) and middle-aged physicians (40-55 years) reported higher annual screening rates relative to older physicians (>55 years) (77% vs 60% vs 44% respectively, p = .03). Among physicians who regularly screened (n = 110), 100% asked quantity-frequency questions, 39% also used the CAGE questions, and 15% also cited use of biochemical markers. CONCLUSIONS: Primary care physicians may 'underdetect' AUDs among older patients. The development of age-specific screening methods and physician education may facilitate detection of older patients with (or at risk for) these disorders.