Objective: To examine the association between use of health care services and health status, sociodemographic, and health care system characteristics in children and adolescents from 11 European countries. Research Design: Cross-sectional surveys in representative samples included using phone or school-based sampling. Subjects: Children and adolescents aged 8-18 years and their parents. Questionnaires were administered in households or at schools in Austria, Czech Republic, France, Germany, Greece, Hungary, Poland, Spain, Switzerland, the Netherlands, and the United Kingdom. Main Outcome Measures: Any visit to ("access") and number of visits ("intensity of use") to health care professionals during the previous 12 months. Results: The study included 16,210 parent-child pairs. In a multivariate analysis, variables statistically associated with access included the following: health status (more disability days, more chronic conditions), sociodemographic characteristics (being younger, being female, having a higher socioeconomic status, or higher parental educational level), and health system variables (higher percentage of public health expenditure, widespread private health care coverage, pediatrician-led system). The strongest association was with disability days [odds ratio (OR) = 6.92; 95% confidence interval (CI) = 5.24-9.14 for 5-15 days]. In the "intensity of use" model, sociodemographic (being younger, strong social support) and health status (chronic conditions, disability days, psychiatric disorders, psychosomatic complaints, poor health-related quality of life) characteristics were associated with greater intensity of use. Health system variables were not significant in this model. Conclusions: The likelihood of contacting the health services is a function of health status, socioeconomic factors, and health system characteristics. Intensity of use among those having made contact is associated with health status and sociodemographic characteristics but not with health system characteristics. Copyright © 2009 by Lippincott Williams & Wilkins.