The objective of this paper is to draw attention to and present statistics on the multiple aspects of violence between parents that should be addressed in research and treatment of such cases. In addition to whether the child had witnessed violence between parents, information is needed on the severity and chronicity of the violence witnessed, and whether only one or both parents were violent. Data on these aspects of inter-parental violence obtained from a sample of 1,313 university students is presented. Thirteen per cent of the students recalled one or more instances of physical violence between their parents when they were age 10 or 13, including six per cent who reported a severe assault. When violence occurred, in about half the cases it was chronic rather than a single isolated instance. In two thirds of the cases the violence was mutual. Both research on witnessing violence between parents and treatment are likely to be enhanced if they take into account the severity, chronicity and mutuality of the violence witnessed by children.