A striking characteristic of the sample was that 83% of the children exhibited clinical levels of conduct problems both at home and in day-care or school settings before treatment. Overall, the combined Parent Training + Classroom Training treatment produced more positive generalisation effects than the Parent Training only group, in particular after treatment. Analyses of differences between group means between pre- and posttreatment were conducted by means of ANCOVAs using pretreatment scores as covariate and treatment condition.