Studies on intra-generational social mobility and its relation with mortality have mainly examined the contribution of mobility to inequalities in mortality. The following register-based study examined the relation between intra-generational mobility and cause-specific mortality adjusting for origin and destination social class. Data includes all individuals working in public organizations and in private firms with >=500 employees (smaller firms are randomly selected). Men (n= 830150) and women (n = 1141192), aged <65 years with an occupational status in 1996, were followed annually until they emigrated, died or at the end of the study (2012). We used discrete time event-history analysis to calculate the adjusted hazard-odds of mortality when upwardly and downwardly mobile, compared to being non-mobile. The results showed that men were at a lower risk of death due to cancer (all-cause, prostate and smoking-related), CVD, IHD, stroke, suicide, accidents and poisoning when they were upwardly mobile (OR 0.42-0.70), while upward mobility among women was related to reduced mortality due to CVD and suicide (OR 0.72; OR 0.51). In men and women, respectively, downward mobility was associated with an increased risk of mortality because of cancer (all-cause cancer: OR 1.21; 1.33, and smoking-related cancer: OR 1.29; OR 1.39), as well as CVD mortality (OR 1.14; OR 1.25), though the confidence intervals slightly overlapped with 1 for the latter cause of death in men. Our findings therefore show that social mobility is relevant to a wide range of causes of death and that the directions of the relationships are consistent with mechanisms involving health selection and/or health reactions to elevated/downgraded social status. However, much of the literature on these mechanisms is oriented toward downward mobility; our finding that mobility is related to mortality predominantly through upward mobility for men invites further research to understand this selection or protection effect more fully.