Although practice guidelines encouraging the screening of patients for intimate partner abuse have been available for several years, it is unclear how well and in which circumstances physicians adhere to them. To describe the practices and perceptions of primary care physicians regarding intimate partner abuse screening and interventions. Cross-sectional survey of a stratified probability sample of 900 physicians practicing family medicine, general internal medicine, and obstetrics/gynecology in California. After meeting exclusion criteria, 582 were eligible for participation in the study. Reported abuse screening practices in a variety of clinic settings, based on a 24-item questionnaire, with responses compared by physician sex, practice setting, and intimate partner abuse training. Surveys were completed by 400 (69%) of the 582 eligible physicians, including 149 family physicians, 115 internists, and 136 obstetrician/gynecologists. Data were weighted to estimate the practices of primary care physicians in California. An estimated majority (79%; 95% confidence interval [CI], 75%-83%) of these primary care physicians routinely screen injured patients for intimate partner abuse. However, estimated routine screening was less common for new patient visits (10%; 95% CI, 7%-13%), periodic checkups (9%; 95% CI, 6%-12%), and prenatal care (11%; 95% CI, 7%-15%). Neither physician sex nor recent intimate partner abuse training had significant effects on reported new patient screening practices. Obstetrician/gynecologists (17%) and physicians practicing in public clinic settings (37%) were more likely to screen new patients. Internists (6%) and physicians practicing in health maintenance organizations (1%) were least likely to screen new patients. Commonly reported routine interventions included relaying concern for safety (91%), referral to shelters (79%) and counseling (88%), and documentation in the medical chart (89%). Commonly cited barriers to identification and referral included the patients' fear of retaliation (82%) and police involvement (55%), lack of patient disclosure (78%) and follow-up (52%), and cultural differences (56%). These findings suggest that primary care physicians are missing opportunities to screen patients for intimate partner abuse in a variety of clinical situations. Further studies are needed to identify effective intervention strategies and improve adherence to intimate partner abuse practice guidelines.