AbstractNumerous studies indicate rumination has a deleterious impact on the course of depressive symptoms. Very little is known about the factors that account for individual differences in the tendency to ruminate, particularly in clinical samples. The aim of this study was to examine the relationship between demographic factors, clinical characteristics of depression, personality and rumination in a clinical sample. Rumination was assessed with the Response Styles Questionnaire in 168 outpatients with a current diagnosis of major depression. Depression characteristics and personality were assessed with both structured clinical interviews and self‐report measures. The results indicate that depression severity and personality predict rumination. Specifically, high initial depression severity, cluster B personality disorder symptoms and low self‐directedness were significant predictors of rumination. There were no age or gender differences in the tendency to ruminate. Personality functioning appears to be an important dimension that may account for individual differences in the tendency to ruminate in depressed outpatients. Copyright © 2009 John Wiley & Sons, Ltd.