Objective: There are only few studies that focused on the personality risk factors for bipolar II disorder. The aim of this study was to find personality risk factors with reference to family history, social circumstances and comorbid symptoms for bipolar II disorder. Method: The most important methodological limitation of studies that investigate risk factors for mood disorders is their limited longitudinal design. In order to address this issue, the data of the Zurich study was used. The Zurich cohort study - a longitudinal study - is composed of a cohort of 4,547 subjects (m=2201; f=2346) representative of the canton Zurich in Switzerland. Results: Frequent ups and downs of mood and family history of neutrasthenia und mania are the most important predictors for experiencing a bipolar II disorder. Conclusion: The probability of developing a bipolar II disorder can be estimated by genetic and personality variable or early prodromal symptoms. There is some evidence suggesting that there are unspecific genetic factors that contribute to the risk for a bipolar II disorder.