The main objective of this study is to determine the effect of socio-familial characteristics, gender, class repetition, and extracurricular activities on school results using a quantitative methodology, based on a non-experimental and correlational study. The sample was composed of 695 students from two schools (middle and high school) in the provincial administration of Mediouna. In order to collect the information, the participants were asked to fill in a questionnaire on their personal and socio-family data. The results obtained were processed by IBM SPSS 26 software. The results showed that the effect of socio-familial characteristics had a partially significant relationship with school grades with a weak effect. Same for class repetition, revision aid and extracurricular activities contribute significantly to school grades variation. Some have highly significant and significant effects for others with a weak partial square condition, on several school subject scores, namely, revision help on the physical education and sports score, extracurricular activities on the physics and chemistry score, etc. In short, considerable effort is needed to better understand the multidimensionality of school success and to ensure effective and relevant educational intervention.