This paper analyses the importance of socioeconomic and cultural background on students’ academic performance. To do so, we relate the scores obtained by Italian secondary school students on the INVALSI Mathematics tests and the Economic, Social and Cultural Status (ESCS) index. The methodology used was regression discontinuity, a method that has emerged as one of the most credible non-experimental strategies for the analysis of causal effects. Specifically, the paper aimed to test whether there was a negative causal effect due to students attending an institution characterized by a “low” Economic, Social and Cultural Status (ESCS) below the threshold set by the Minister of Education and Merit. The results show that this causal effect is present and statistically significant, reinforcing our thesis that socioeconomic and cultural background impacts students’ academic performance.