Recently, there has been an increase of research interest in the nature of the relationship between the concept of "competence" and mental health and disorder. For a large sample of adolescents studied at ages 11 and 15 years, we developed indices of social competence at each age based on measures of social attachment and involvement in activities. There was a significant association between competence and "externalizing" disorders at both ages. Competence was related to "internalizing" disorder only at age 11. Preadolescent social competence did not predict later disorder at age 15 in the sample as a whole. However, externalizing disorder at age 15 was predicted by presence of disorder together with low social competence in preadolescence.