Data were examined from clinical files of 306 adult male employees referred by their employer for a mental health and risk assessment after a recent workplace altercation (the index incident) involving either an observed aggressive (e.g., verbal outburst or property damage) or violent (e.g., assault or attempted assault) act directed at a fellow employee. Personal and work-related factors were examined across two comparisons to better understand the factors that distinguished aggressive, violent, and repeatedly violent employees. The first comparison distinguished 219 (72%) employees who were aggressive from 87 (28%) who were violent during their index incident. Results showed that violent employees were more likely to be in a common-law or married relationship and more likely to have previous physical workplace incidents, but were less likely to have a Diagnostic and Statistical Manual of Mental Disorders (DSM) Axis I diagnosis and a history of threats at the workplace. The second comparison distinguished 61 (67%) employees who were violent once (nonrepeaters) from 30 (33%) employees who were violent more than once (repeaters). Employees who engaged in repeated violence were found more likely to have experienced early physical abuse, have substance use problems and anger problems, and were more likely to have a DSM Axis II diagnosis. They were also more likely to have problematic workplace histories characterized by threats, intoxication, and suspensions and/or terminations.