This article presents a study designed to study the behavior of foster children (healthy and with disabilities (HIA)) before and after their families participated in an intervention program based on a methodology which supported interaction between children and parents. The sample consisted of 326 children (201 children from substitute families; 125 from biological families). The study was conducted using the method of assessing negative manifestations of attachment behavior (K. Reber). The result is that in adopted children (both healthy and with disabilities) negative manifestations of behaviour had decreased after participation in an intervention program. However, the decrease occurred in the mean values of behavioral disorders at middle and higher levels of participation of families in the program, but not in the minimal. The results confirm the thesis that it is extremely important to involve substitute families in the work of support services and to ensure their stable participation in the proposed activities.