Reading skills and social-emotional competencies are two important skills for both academic achievement and long-term quality of life. The present study evaluated the effects of a school-based intervention to promote reading skills and social-emotional competencies in young adolescents from urban, low socioeconomic status (SES) communities in their first year of secondary education. A small group intervention was conducted, using book clubs in which students read and discussed literature with the objective to enhance reading attitude, reading comprehension and social-emotional competencies. Participants were randomly allocated to either the book club intervention condition (n = 50) or a business-as-usual control condition (n = 40). Results revealed that the intervention group accrued significant greater gains than the control group in (recreational) reading attitude, reading comprehension and social emotional competences. Highlights--(1) What is already known about this topic: (a) The transition from primary to secondary education is accompanied by a sharp decline in reading attitude and a rise in demands on young adolescents' social-emotional competencies. (b) Qualitative research suggests book clubs can be an educational tool to enhance both reading behaviour and social-emotional skills. (2) What this paper adds: A bibliotherapeutic book club intervention can be an effective tool to improve reading attitudes, reading comprehension and to strengthen social-emotional competencies in young adolescents from low SES areas. (3) Implications for theory, policy or practice: This study supports the inclusion of bibliotherapeutic book clubs in the secondary education curriculum as a mean to address both reading behaviour and social-emotional competencies, two skills that are important for adolescents' academic success.