One of the most serious occupational problems in the workplace is the occurrence of violent assaults. This study examined 2028 workers' compensation claims of workplace violence from Oregon between 1990 and 1997, and used Current Population Survey data for risk analysis. The rate of workplace violence was 1.86 per 10,000 employees annually (95% confidence interval, 1.78-1.94), with females and workers under 35 years of age experiencing the most violence. The average claim resulted in approximately 40 days of indemnity and $6200 in costs. Workers on evening and night shifts had significantly higher rates of being victims of violence, as did those working on weekends. Preventative interventions should be targeted at younger workers and those with less tenure. Special measures should be focused on ensuring the safety of evening/night-shift workers and weekend employees.