Trait emotional intelligence (EI) refers to a constellation of emotional self-perceptions located at the lower levels of personality hierarchies. This study investigated the predictive and incremental validity of this construct in a sample of 1140 pupils aged 11-13 years. Trait EI showed strong concurrent and predictive validity in relation to three measures of socioemotional competence: self-reported psychopathology as assessed by the Strengths and Difficulties Questionnaire, a sociometric measure of peer relations, and a peer-assessed measure of social behavior. Socioemotional measures were taken twice over a period of seven months. Structural equation modeling revealed trait EI and IQ effects on socioemotional competence (SEC), the former being stronger than the latter. Hierarchical regression analyses suggested an association also of trait with level of change in SEC (controlling for both IQ and SEC at time 1). The findings corroborate an important role for trait emotional intelligence in peer relations and socioemotional competence.