BACKGROUND: Low socioeconomic status and frailty are factors of vulnerability in old age. They are both well-known risk factors of death. On the other hand, low socioeconomic status has been reported as a predictor of frailty, which questions the relationship between socioeconomic status, frailty and death. OBJECTIVES: The aim of this work was to explore the respective contribution of psychosocioeconomic precariousness - which covers socioeconomic status and also psychosocial vulnerability - and frailty in predicting mortality. DESIGN: Prospective population-based study. SETTING: Three-City (3C) Bordeaux study, France. PARTICIPANTS: The sample consisted of 1586 subjects aged 65 or older. MEASUREMENTS: Psychosocioeconomic precariousness was assessed utilizing a structured instrument which assessed poor socioeconomic status, and psychosocial vulnerability. Frailty status was defined by Fried's phenotype. RESULTS: After 14 years of follow-up, 665 deaths (42%) occurred. Psychosocioeconomic precariousness and frailty had both an independent contribution to mortality prediction (hazard ratio (HR) 1.51 (95% confidence interval (CI) 1.11-2.07)) and (HR 1.68 (95% CI 1.19-2.38)), respectively. Such relationships were adjusted for age, sex, disability, and comorbidities. No interaction term was found between precariousness and frailty. CONCLUSIONS: If psychosocioeconomic precariousness and frailty are both aspects of vulnerability in old age, they have a non-overlapping contribution in the prediction of mortality. These findings emphasize the importance of considering both psychosocioeconomic precariousness and frailty when identifying elderly people at risk of death.< Réduire