Abstract Background Financial stress may have adverse health effects. The main aim of this study was to investigate whether having a cash margin and living alone or cohabiting is associated with incident cardiovascular disease (CVD) and all-cause mortality. Methods Representative population-based prospective cohort study of 60-year-old women (n = 2065) and men (n = 1939) in Stockholm County, Sweden. National registers were used to identify cases of incident CVD (n = 375) and all-cause mortality (n = 385). The presence of a cash margin was determined in the questionnaire with the following question: Would you, if an unexpected situation occurred, be able to raise 10 000 SEK within a week? (This was equivalent to US$ 1250 in 1998). Results Compared with cohabiting women with a cash margin, the risk of all-cause mortality was higher among cohabiting women without a cash margin, with hazard ratios (HRs) of 1.97 (95% confidence interval (CI) 1.06–3.66). Using cohabiting men with cash margin as referent, single men without a cash margin were at an increased risk of both incident CVD and all-cause mortality: HR 2.84 (95% CI 1.61–4.99) and 2.78 (95% CI 1.69–4.56), respectively. Single men with cash margins still had an increased risk of all-cause mortality when compared with cohabiting men with a cash margin: HR 1.67 (95% CI 1.22–2.28). Conclusions Financial stress may increase the risks of incident CVD and all-cause mortality, especially among men. Furthermore these risks are likely to be greater in men living in single households and in women without cash margins. Living with a partner seems to protect men, but not women, from ill-health associated with financial stress due to the lack of a cash margin.