Social fears are common among adolescents and may considerably impair their lives. Even so, most adolescents do not seek professional help for these difficulties, making it important to promote evidence-based and preventive interventions in community samples. This research presents the effectiveness of an intervention with a group of five female adolescents who reported serious interference of their social fears in their daily life. At post-intervention, effectiveness was noticeable by high recovery, reliable individual change, and intragroup statistical change. The intervention showed impact for measures of social anxiety, avoidance, and assertiveness, and such impact was steady at 3-month follow-up. These findings add to the cumulative and transcultural evidence on the effectiveness of Skills for Academic and Social Success (SASS).