Psychological factors and stressful life events (LE) are considered to play a role in the onset of the metabolic syndrome (MS). We tested the association between LE and cortisol, a marker of chronic stress, with the risk of developing MS and their interaction. From a total number of 2906 men who completed a screening for the early detection of prostate cancer, 149 healthy men (mean ± SD age, 58.6 ± 7.7 years) were included in this study. Participants were assessed by the Holmes and Rahe questionnaire about their experience of LE during the previous 1-5 years. MS was diagnosed according to National Cholesterol Education Program-Adult Treatment Panel III (ATP-III) and International Diabetes Federation (IDF) criteria. Serum cortisol was measured at 08:00-09:00 h. Participants with MS (IDF criteria) reported significantly more past LE (p = 0.009) and greater summed weight of LE (p = 0.049) than those without MS. Furthermore, LE interacted with cortisol in relation to MS: in men with increased serum cortisol levels ( ≥ 13.7 μg/dl), number of LE significantly predicted MS-status (relative risk (RR) = 1.16, p = 0.03), whereas in men with low cortisol, LE were unrelated to MS (p = 0.52). We conclude that LE were significantly more prevalent in men with the MS than without the MS, according to IDF criteria, independent of the effects of age and body mass index, especially in men with increased serum cortisol levels.