IntroductionMany interventions have been developed to reduce the problems of families with multiple problems (FMP) and to prevent children's out-of-home placement. Evidence is increasing about the effects of these interventions, but is scarce about the elements of care determining these effects. The aim of this study is to examine to what extent provided elements are associated with improved outcomes for FMP. MethodsWe collected data from 499 FMP that received an intensive family intervention. Practitioners collected information every four weeks about provided practice elements (content), the method of provision, recipients and program elements (structure). Parents filled out questionnaires at the start, at the end, and three months after conclusion of the intervention. We used the Reliable Change Index (RCI) to discriminate improvement and non-improvement regarding four outcomes: child externalizing behavior, child internalizing behavior, parenting stress, and social contacts. ResultsWe found that parenting stress was more likely to be reduced when skills were more often practiced with the family. We found no associations between practice elements, methods or recipients and other outcomes. We neither found associations between provided program elements and improved or non-improved outcomes. ConclusionOur research shows that the majority of the individual elements show no or only very limited effect, except for practicing skills with family members. To gain more insight into the contribution of elements of interventions for FMP, we recommend looking further into the association between provided elements and other factors such as the therapeutic alliance and severity of problems.