Study findings of interrelated factors in the link between violence and methamphetamine use suggest that the frequency of violence among study participants may be less an issue of methamphetamine use than the negative behavioral consequences of a pattern of long-term polysubstance (both legal and illicit) use. Among the 16 participants (8 men and 8 women) in Arkansas and 23 participants (14 men and 9 women) in Kentucky, a total of 12 participants (6 men and 6 women) reported 13 episodes of involvement in violence related to methamphetamine use, and another female participant reported an incident that involved methamphetamine and another substance. The violent incidents included eight arguments, three incidents of property damage, and three fights/assaults/injury. Twenty participants (11 men and 9 women) reported involvement in 25 violent episodes linked to substances other than methamphetamine. The non-methamphetamine-related violent episodes included 12 fights/assaults/injury, 8 arguments, and 5 incidents of property damage. Several overlapping factors related to career substance-use patterns may explain the relatively lower frequency of methamphetamine-related violence compared to other substances used. The widespread availability and use of methamphetamine were relatively recent at the time of baseline interviews compared to the availability of other substances; and violence could be linked to other substances within the context of the ongoing use of methamphetamine as a primary drug. Among study participants, most violent episodes specifically linked to methamphetamine use, except for some arguments, occurred after the binge use of the drugs. The associated lack of sleep, irritability, paranoia, or hallucinations appeared to be precursors of reported violence. Study participants were recruited using respondent-driven sampling, a modified form of snowball sampling. Follow-up interviews were conducted 12 to 24 months after baseline interviews. 2 tables and 36 references