Several studies have focused on the association between parental and personal socioeconomic position (SEP) and health, with mixed results depending on the specific health outcome, research methodology and population under study. In the last decades, a growing interest is given to the influence of intergenerational mobility on several health outcomes at young ages. This study addresses the following research question: Is educational intergenerational mobility associated with all-cause and cause-specific mortality in young adulthood? To this end, the Belgian 1991 and 2001 censuses are used, providing characteristics of young persons at two time points (T1 = 01/03/91;T2 = 01/10/01) and follow-up information on mortality and emigration between T2 and 31/12/09 (T3). The study population consists of all official inhabitants of Flanders and the Brussels-Capital Region at T2, born between 1972 and 1982 and alive at T2. Parental and personal education are divided into primary (PE), lower secondary (LSE), higher secondary (HSE) and higher education (HE). We analyse mortality between T2 and T3 calculating age-standardised mortality rates (ASMRs) and using Cox regression (hazard ratios = HR). Personal rather than parental education determines the observed mortality rates, with high all-cause mortality rates among those with PE, irrespective of parental education (e.g., among men ASMRPE-PE = 200.0 [95% CI 158.0-241.9]; ASMRHE-PE = 319.7 [183.2-456.3]) and low all-cause mortality among those in higher education, regardless of parental education (ASMRPE-HE = 41.7 [30.8-52.6]; ASMRHE-HE = 38.0 [33.2-42.8]). There is some variation by gender and according to cause of death. This study shows the strong association between personal education and young-adult mortality.