The current study presents a review of intervention studies conducted in the Low Countries (i.e., The Netherlands and Flanders) focusing on social-emotional behaviors in the school. The primary purpose of this review was to assess whether studies included an operational definition of the intervention under study and reported data on the implementation of intervention. The former is important with regard to replication, whereas the latter is required to support the claim that the intervention under study actually produced the changes in the behavior targeted by the intervention. A total of 102 studies were reviewed and published in international or Dutch/Flemish journals between 2000 and 2015. Results indicate that a substantial amount of studies included an operational definition of the intervention or referred to its source (82.3%), but only a minority of studies provided quantitative or qualitative intervention integrity data (32.4%). It was concluded that researchers in the Low Countries should raise the level of attention to intervention integrity issues while journals should adopt more stringent criteria for evaluating intervention integrity data.