Previous studies that were carried out to investigate the prevalence of mental health problems among children and adolescents in Germany are based on regional samples, limited age ranges or used ambiguous case definitions. In the Hamburg Health Survey, data on emotional and behavioral problems were collected by a parent and a child questionnaire on the basis of a nationwide representative sample of 1950 families with children and adolescents between the ages of 4 and 18. Besides study-specific items, the Child Behavior Checklist and the Youth Self-Report were used. The symptom and total prevalence rates of clinically significant cases as well as dimensional descriptive statistics and coefficients of agreement between parent- and self-report were calculated. The results indicate that children and adolescents in Germany suffer from a variety of emotional and behavioral problems which require differentiated interpretations depending on their symptom, age and sex. In accordance with the respective case definition, between 10 % and 18% of the children and adolescents were considered to have a clinically relevant score requiring counseling, diagnostics or treatment. The agreement between parent- and self-report scores in the middle range using dimensional statistics and in the lower range for the case definitions. The results are discussed in comparison with German and international studies carried out so far. An increase of mental health problems over the past decades cannot be deduced from the data. Procedures which allow the standardization of future investigations are recommended and possibilities to improve current mental health care utilization are discussed.