Violence is a core public health issue which is linked to substance misuse in complex and interactive ways. Qualitative data on 220 violent episodes was collected over a three year period from service users and staff at Dublin methadone clinics. Inductive analysis of the data led to a typology of violent events, which may help to enhance clinical and social responses to the problem. Witnessed clinic episodes were interpreted as consequences of disturbed individual states or traits, or in terms of immediate situational conflict. Client narratives were construed as illustrations of family violence, local feuds, delinquency, dealing, retribution and abuse. A variety of pertinent clinical and organisational solutions are put forward in the context of a necessary community development and social inclusion process.