The International Delinquency Project involves assessment of mental health problems in juvenile delinquents and the implication these problems carry for their future psychosocial functioning and for recidivism. The data for this project come from two data sources - data on 370 incarcerated delinquent youth from Arkhangelsk, Russia, collected by Drs. Vladislav Ruchkin and Roman Koposov in 1999-2000, and data on 80 adjudicated juvenile delinquents from Antwerp, Belgium, collected by Dr. Robert Vermeiren and his colleagues. After a series of analyses, several papers on the predictive role of mental health problems and neuropsychological factors for future recidivism (Belgium) and on the role of psychiatric comorbidity for psychosocial functioning of delinquent youth (Russia) have been accepted or are in the process of review.