This article elaborates on previous research showing that educational achievement is negatively related to poor mental health during adolescence and positively related to the family's socioeconomic resources. We examine (i) the potential moderating effects of family resources on the negative relationship between educational achievement and poor mental health and (ii) the impact of resources linked to the mother and father, respectively, on educational achievements. We use register data that cover all children born in Sweden in 1990 who still lived there in 2010 (n = 115,882). We use two dependent variables -- upper secondary school graduation and grade point average (GPA) -- and analyse the performance of girls and boys separately. Our results indicate that the impact of mothers' socioeconomic resources on children's school performance is stronger overall than that of fathers' resources. The compensatory effects of family socioeconomic resources on the risk of failure to graduate are more pronounced amongst girls than boys. With regard to GPA, compensatory effects are largely absent.