This study examined the concurrent relationship between participation in extracurricular activities and externalizing and internalizing problems and social school behavior in a Spanish community sample, separately for boys (n5439) and girls (n5428), enrolled in 2nd, 4th, or 6th grades. Weekly participation in extracurricular activities was related to better emotional and behavioral adjustment and social competence. Overall, the relations were low and different according to gender, type of activity, and informant. Better adjustment was more related to participation in sports activities in boys and to participation in nonsports activities in girls. Size effect was higher for girls and decreased for both boys and girls when parental education and parenting practices were considered. Findings supported previous results obtained in American adolescents. © 2010 Wiley Periodicals, Inc.