Introduction: Evidence has remained scarce whether teaching practices might be linked to students' educational equality. This study investigated (i) whether student-oriented teaching practices are associated with students' learning outcomes in mathematics, and (ii) whether student-oriented teaching might increase equality in learning outcomes between students with different backgrounds. Method: We used the Finnish PISA 2012 data (N=5052-5660) that provides a nationally representative sample of the Finnish 15-year-old students. The data were analyzed using structural equation models. Results: Frequent student-oriented teaching practices were associated with students' weaker learning outcomes in mathematics. The effect of frequent student-oriented teaching practices was especially negative among students with risky backgrounds (i.e. risky family structure, low family wealth, low maternal education, immigrant status, student's previous truancy behavior at school). Our additional analyses showed that also frequent inquiry-based teaching practices were related to weaker learning outcomes in science. Discussion and Conclusion: In conclusion, student-oriented teaching practices appear to be linked with students' weaker learning outcomes in comprehensive school. Student-oriented teaching may expand the gaps in learning outcomes between students coming from different backgrounds.