Background: The impact of organizational climate on physicians and their patients is not well understood. The Minimizing Error, Maximizing Outcome (MEMO) Study investigates this question through a conceptual model that relates office working conditions to quality of care, as mediated by physician reactions. Methods: MEMO is a longitudinal study of physicians and patients in New York, Chicago, and the state of Wisconsin, including Milwaukee and Madison. Physician surveys assessed office environment and organizational climate (OC). Stress was measured using a 4-item scale, past errors were self reported, and the likelihood of future errors was self-assessed using the OSPRE (Occupational Stress and PReventable Error) measure. Factor analysis revealed new domains of OC. Regression analyses assessed predictors of stress, past errors, and future errors. Results: Among 420 physician respondents, predominantly from general medicine and family medicine practices, 38 percent described their office environment as busy, tending toward chaotic, while another 10 percent described their office environment as hectic or chaotic. Sixty-one percent agreed their work was stressful; 27 percent noted burnout symptoms; and 31 percent of respondents said they were at least moderately likely to leave their jobs within 2 years. The domains of OC (with related Cronbach's alpha values) were: leadership/governance (.86), quality emphasis (.86), belonging/trust (.79), information/communication (.68), and cohesiveness (.66). Chaotic office atmosphere was strongly associated with physician stress (P = .001), while a lack of quality emphasis was associated with past errors (P < .005), and a lack of emphasis on information and communication was associated with a higher likelihood of future errors (P < .02). Less trust in the organization was associated with an intent to leave (P = .001). Other variables associated with physician outcomes included age, gender, ethnicity, work hours, work control, inadequate resources, and a lesser emphasis on diversity. Conclusions: Physician stress is prevalent in primary care; stress and the likelihood of making errors are associated with organizational climate and office environment. Primary care offices could be made safer by emphasizing information systems, promoting a culture of quality, and improving the hectic environment.