This study explored the directionality of the relations between global life satisfaction (LS) and internalizing and externalizing behaviors using a sample of regular education students who were initially enrolled in Grade 7 ("n" = 470). Self-report measures of internalizing and externalizing behaviors and LS were administered on 2 occasions, 6 months apart, to students from a Southeastern U.S. middle school. Short-term longitudinal analyses revealed that neither externalizing behaviors nor internalizing behaviors at Time 1 predicted LS at Time 2. However, LS at Time 1 predicted externalizing behaviors at Time 2. LS at Time 1 also predicted internalizing behaviors at Time 2, but the results were moderated by student gender. At higher levels of LS, boys reported lower levels of internalizing behaviors at Time 2. The overall results suggested that lower levels of LS are an antecedent of increased maladaptive behaviors among early adolescents. Alternatively, higher levels of LS may be a protective factor against subsequent externalizing behaviors among boys and girls and internalizing behaviors among boys. Furthermore, the results provide further support for the discriminant validity of positive and negative measures of mental health and suggest that LS measures may provide useful information for comprehensive adolescent health screening and monitoring systems.