Extracurricular activities play an important role in the school lives of students. To understand this effect, the authors of this article consider public schools in Azerbaijan and analyse the effect of extracurricular activities on students’ academic performance. They conducted a study investigating three groups of extracurricular activities: sports, fine arts and student clubs. For data on academic performance, they used results of a centralised state school examination which assesses students in two subjects: language of instruction (either Azerbaijani or Russian) and mathematics. The results of this study show that some extracurricular activities have a positive effect on students’ academic performance, while others show no effect. Moreover, the authors consider the number of different extracurricular activities a student takes part in and analyse the significance of this number in predicting student success.