The descriptive analyses show that misbehavior and delinquency are common among the participants in this study. More than two-thirds of the students reported at least one of the investigated misbehaviors, and almost one-half reported that they had been involved in some delinquent activity. The most common misbehaviors and delinquent activities were fighting without injury, bullying, petty theft of items worth less than 5 euro, and vandalizing and graffiti. Advance criminal activities, like burglary, robbery, and aggravated theft, were reported by only one or a few percent of the respondents, and threatening teachers and injuring others by a somewhat higher proportion of the students. Despite several noted limitations, the results have improved insights in several ways. The findings suggest that there is a general relationship among more types and categories of misbehavior and delinquency than was known from earlier studies that focused mainly on bullying and violent types of delinquency. At the same time, it was found that this relationship is less strong and more complex than existing empirical studies and criminological perspectives suggest. This study is among the first to investigate the relationship between misbehavior conducted within the school and delinquent behavior outside school. The study used cross-sectional and longitudinal data collected among secondary school students in the Netherlands. About 2,000 were surveyed in 2002 and 1,385 students were followed up in 2003. The questionnaire covered 9 types of misbehavior at school and 12 types of delinquency outside school. Tables, appendix, notes, and references