A patient safety movement that began with a 1999 Institute of Medicine report on the prevalence of preventable medical errors has spawned both policy to change health care systems and a growing body of literature aimed at understanding the causes of such errors. A 2003 AHRQ systematic review investigated the role that workplace conditions play in explaining patient safety and found that workloads, work schedules, lengths of work shifts, and stress levels affected rates of non-fatal adverse outcomes, mortality rates, medication errors, and other patient safety measures. However, much of this evidence relies on studies based in hospitals and focuses on nurse and resident staffing or is based on studies in non-healthcare settings. A large body of evidence has shown clear linkages between workplace conditions and employee satisfaction and stress in a wide variety of organizational and industry settings. In the healthcare industry, increasing interest in understanding these linkages has stemmed from the idea that healthcare providers' working environments also affect important patient outcomes, including safety, quality of care and satisfaction. Additionally, meeting objectives of the current healthcare reform to increase healthcare quality by increasing the availability of primary care providers and making care safer, more efficient, effective and patient-centered hinges on the ability to deal with the documented shortage of primary care providers in the U.S. and at the same time improve patient outcomes. The purpose of this report is to systematically review the evidence on the role of primary care providers' workplace conditions in influencing patient outcomes. The focus on primary care providers' work environment will provide evidence on increasing healthcare quality. While the focus of this review is on patient outcomes, we do discuss implications for providers and recent review studies that highlight the importance of provider wellness as a component of high quality care. Results from this review may inform policymakers as they endeavor to implement aspects of the healthcare reform related to increasing the supply of primary care providers and improving patient outcomes. Following the 2003 AHRQ report, we focused on the following workplace conditions: 1) human resource practices 2) organizational culture, and 3) physical environment, but restricted our review to studies on primary care providers (physicians, physician assistants, and nurse practitioners) in ambulatory care settings. Note that the workplace condition constructs, specifically "human resources practices" and "organizational culture", may overlap. However, our categorization of these workplace conditions does not affect the evidence presented; it merely serves as a way to organize a long list of workplace conditions. We conceptualized primary or ambulatory care to include clinics and providers that serve as a first point of contact for patients where common illnesses and conditions are treated. Therefore, we excluded studies that focused on one specific disease, even chronic conditions that may be managed by a primary care provider, or one specific patient population (e.g. diabetics). The key questions were: #1. How are human resources (HR) practices, such as skill levels, training, workload, hours worked, autonomy, and electronic medical records/systems, associated with patient outcomes? a. quality of care (access and effectiveness) b. safety (medication errors) c. patient satisfaction (with provider, with clinic/practice) #2. How are other working conditions, such as organizational culture or physical environment, associated with patient outcomes? a. quality of care (access and effectiveness) b. safety (medication errors) c. patient satisfaction (with provider, with clinic/practice) #3. In studies that report provider outcomes, how are working conditions associated with provider outcomes (e.g., job satisfaction, productivity, pay)?