Objective: Identify the exposure effects of job family, patient contact, and supervisor support on physical and non-physical work related violence. Design: Cross sectional study of employees in a Midwest health care organization, utilizing a specially designed mailed questionnaire and employer secondary data. Subjects: Respondents included 1751 current and former employees (42% response rate). Results: Physical and non-physical violence was experienced by 127 (7.2%) and 536 (30.6%) of the respondents, respectively. Multivariate analyses of physical violence identified increased odds for patient care assistants (odds ratio (OR) 2.5, 95% confidence interval (CI) 1. 1 to 6.1) and decreased odds for clerical workers (OR 0.1, 95% CI 0.03 to 0.5). Adjusted for job family, increased odds of physical violence were identified for moderate (OR 5.9, 95% CI 2.1 to 16.0) and high (OR 7.8, 95% CI 2.9 to 20.8) patient contact. Similar trends were identified for non-physical violence (OR 1.4, 95% CI 1.1 to 2.0 and OR 1.7, 95% CI 1.3 to 2.3). Increased supervisor support decreased the odds of both physical (OR 0.7, 95% CI 0.6 to 0.95) and non-physical violence (OR 0.5, 95% CI 0.4 to 0.6), adjusting for job family and demographic characteristics. Conclusions: Increased odds of physical violence were identified for the job family of nurses, even when adjusted for patient contact. Increased patient contact resulted in increased physical and non-physical violence, independent of job family, while supervisor support resulted in decreased odds of physical and non-physical violence.