This study investigates the relationship between parental social class and young people's school examinations in England. This study uses a specialist data resource from the UK Household Longitudinal Study (Understanding Society) and linked administrative data from the Nat­ional Pupil Database. The main aims are to better understand the effects of parental social class on Key Stage 2 results in primary school (at age 11) and General Certificate of Secondary Education (GCSE) results in secondary school (at age 16) (i.e. two critical stages in a pupil's educational life course). There is a strong positive association between pupils' Key Stage 2 scores and GCSE scores. There are significant parental social class inequalities in GCSE outcomes, and these divisions have clearly opened up by the end of primary school. This result is consequential for the development of policies that are designed to tackle social inequalities.