Results of the study showed that among children in foster care the use of cigarettes, alcohol, and drugs was more common. These behaviors were found to be most frequently practiced in situations connected to social gatherings, and the most important predictor of current smoking was the number of peers who smoked. An analysis of the findings found that there were two different motives for trying cigarettes for the first time: experimenting due to curiosity (younger youth) and the wish to follow fashion trends with a group of peers (older youth). In the group of children living in foster homes, the proportion of those who consumed cannabis was significantly higher than in the group of children living with their biological families. A significant percentage of the studied children stated that they used tobacco, alcohol, or cannabis prior to some stressful event. Children in foster homes stated more frequently that they felt lonely and that they lacked self-confidence. Loneliness was a significant predictor of current smoking in the group from foster homes. The results suggest that prevention programs emphasizing social groups living under adverse conditions is needed. Previous studies indicate that adolescents from non-intact families and those who have lived in a stepfamily during childhood tend both to drink more and start at an earlier age, and were more likely to use tobacco, alcohol, and illicit drugs at the age of 18. The study was conducted in Belgrade, Serbia and Montenegro during 2003-2004. The study sample consisted of 58 children living in foster homes and 245 children living with their parents. Tables, references