BACKGROUND: To investigate risk factors associated with low subjective well-being (SWB) in men and women (≥65 years) separately with a special focus on emotional distress. METHODS: A cross-sectional analysis was conducted among 3602 participants (50.6% women) aged 65-90 years (mean age 72.8 years, SD ± 5.8) from the population-based KORA-Age study conducted in 2008/2009. SWB was assessed using the WHO-5 well-being index (score range: 0 to 100). SWB was dichotomized into "low" (score ≤ 50) and "high" (score > 50) SWB. The association between potential risk factors and SWB was assessed by logistic regressions analyses. Population-attributable risks (PARs) were calculated. RESULTS: Low SWB was significantly higher in women than in men (23.8% versus 18.2%; p < 0.0001). The logistic regressions analyses revealed low income, physical inactivity, multimorbidity, depression, anxiety and sleeping problems to be associated with low SWB in both sexes. Living alone increased the odds of having low SWB in women, but not in men. Depression and anxiety were the strongest risk factors of low SWB among men (depression: OR: 4.19, 95% CI: 1.33-13.17, p < 0.05; anxiety: 8.45, 5.14-13.87, p < 0.0001) and women (depression: 6.83, 2.49-18.75 p < 0.05; anxiety: 7.31, 5.14-10.39, p < 0.0001). In both sexes, anxiety had the highest population-attributable risk (men: 27%, women: 41%). CONCLUSION: Our results call out for an increased focus on mental health interventions among older adults, especially for women living alone. Further research is needed to understand the paradoxical pattern of discrepant subjective well-being versus objective health in age.