The study found a reciprocal relationship between conduct problems and school connectedness. Conduct problems contributed to a change in school connectedness 1 year later, and school connectedness contributed to a change in subsequent conduct problems 1 year later. According to social control theory, early adolescents who are connected to the school are more likely than their peers to follow the school's rules and regulations and may consequently manifest fewer conduct problems. Such adolescents may also refrain from engaging in aggressive and antisocial behaviors, because they internalize the prosocial expectations, norms, and values of their teachers and nondeviant peers. From another perspective, the positive influence of school connectedness on conduct problems may be a function of the degree to which the middle school is meeting the needs of its students. Findings also suggest that adjustment problems and related conduct problems brought to the school increase the risk that a student will have poor school connectedness. Students may enter middle school with varying levels of pre-existing adjustment problems that may influence the quality of interpersonal relationships with other students and their ability to comply with school behavioral and academic expectations. Participants were 500 10-14-year-old students attending all 3 middle schools in a suburban school district in central Texas. They were involved in the first and second waves of a larger longitudinal study. School connectedness was measured with five items from the National Longitudinal Study of Adolescent Health. Conduct problems were determined from the self-report Strengths and Difficulties Questionnaire; and depressive symptoms were measured with the Children's Depression Inventory. 1 table, 2 figures, and 44 references