Much of the research on violence in the health care sector has focused on the immediate and long-term effects of patient violence on staff victims. There is a lack of studies, however, examining whether individual reactions to violent episodes, such as anger and increased fear in one's work, have any measurable effect on staff behaviour toward their patients, and ultimately on the quality of patient care. The aim of the present study was to investigate whether an association exists between staff experiences with violence and patient-rated quality of patient care. A theoretical model was presented, suggesting that violence or threats experienced by health care staff have a negative effect on the quality of health care services offered, as measured by patients. In addition, it was theorised that there would be an association between staff work environment and staff reports of violence. Six questionnaire studies, three concerning hospital staff's views of their work environment and three dealing with patients' perceptions of the quality of care, provided the data for evaluating the model. Work environment and quality of care studies were carried out simultaneously at a single hospital in 1994, 1995, and again in 1997. Regression analysis was used to see which combination of work environment and quality of care variables would best predict a positive overall grade for quality of care from the patient perspective. Violence entered consistently as an important predictor into each of the three best regression equations for 1994, 1995, and 1997, respectively. The results of this analysis suggest that the violence experienced by health care staff is associated with lower patient ratings of the quality of care. The study indicates that violence is not merely an occupational health issue, but may have significant implications for the quality of care provided.