Purposes/Aims: The purpose of this study was to determine the professional, workplace and personal factors that significantly relate to advanced practice nurses' (APNs) self-efficacy to treat intimate partner violence (IPV).Rationale/Conceptual Basis/Background: IPV affects one in three women in the U.S. and is the leading cause of maternal death during the prenatal and first year post-partum periods. Older women victims suffer earlier death from all causes. IPV is under diagnosed and undertreated based on large surveys of emergency departments and outpatient clinics. APNs are providing health care to large numbers of potential victims, thus they are important as diagnosticians and treating clinicians. Methods: A national quantitative survey of APNs was performed with the aim of obtaining APNs from diverse specialties, geographic areas, and demographics within the U.S. Participants completed an electronic survey using modifications of standardized questionnaires on professional factors of hours of previous IPV education, IPV knowledge, years in practice, current practices, role belief, and self-efficacy to treat IPV. A new scale was developed to test workplace factors of screening tools and protocols, institutional, and community supports. Personal factors of age, gender, past IPV experience, vicarious trauma (VT), resilience, and general self-efficacy were tested using previously validated tools. Results: A sample of 494 APNs was obtained. Respondents were demographically representative of U.S. practicing APN population. Findings from this study indicate that APNs' current self-reported practice behaviors regarding IPV, total hours of IPV education, age in years, role belief, resilience, absence of VT and IPV knowledge are the most significant contributors to APNs' self-efficacy to treat IPV. Implications: APNs with strong clinical experience with IPV, more hours of IPV education, older age, belief that it is their role to treat IPV, and greater IPV knowledge, reported the best self-efficacy to treat IPV. Educational institutions should provide more formal and ongoing education in IPV. VT in APNs who treat IPV should be further explored. Health care organizations should provide continuing IPV education and provide work environments that promote the treatment of IPV for APNs to effectively identify and engage in treatment those patients who may be victims.