Workplace violence is becoming increasingly recognized as a serious problem in health care settings. All 628 workers' compensation assaults claimed by minority Los Angeles County health care workers from 1986 through 1990 were abstracted. Population-at-risk data from county personnel computer tapes provided denominators by age, sex, race, job classification, and type of facility. Rates varied by type of facility (rate ratio = 38 for psychiatric hospitals vs public health facilities) and varied by job, with inpatient nursing attendants having the highest rate for caregivers. Most assaults were committed by patients (86%), followed by coworkers (8%). The average cost of an assault ($4879) was relatively low but related to the costlier problem of work-related emotional illness.