Background: Socioeconomicinequalities inmortality arewell established, yet the contribution of intermediate risk factors that may underlie these relationships remains unclear.We evaluated the role of multiple modifiable intermediate risk factors underlyingsocioeconomicassociated-mortality and quantifiedthe potentialimpact of reducing early all-cause mortality by hypothetically altering socioeconomic risk factors. Methods: Data were fromsevencohort studies participating in the LIFEPATH consortium (total n=179,090). Using bothsocioeconomic position (SEP) (based on occupation) and education, we estimated thenaturaldirect effect on all-cause mortality, and thenatural indirect effect via the joint mediatingrole of smoking, alcohol intake, dietary patterns, physical activity, body mass index,hypertension, diabetes, and coronary artery disease.Hazard ratios(HR)were estimated, using counterfactual natural effect modelsunder different hypothetical actions of either lower or higher SEP or education. Results: Lower SEP and educationwereassociated with anincreaseinall-cause mortalitywithin an average follow up time of 17.5 years.Mortality wasreducedviamodelled hypothetical actions of increasing SEP oreducation. Through higher educationtheHR was0.85(95% confidence interval (CI) 0.84, 0.86) for women and 0.71(95% CI 0.70, 0.74)for men,compared to lower education. In addition, 34% and 38% of the effect was jointlymediatedfor womenand men, respectively. The benefits from alteringSEP were slightly more modest.Conclusions: Theseobservational findings supportpoliciesto reducemortalityboththrough improving socioeconomic circumstances and increasing education,andby altering intermediaries, such as lifestyle behaviours and morbidities.