Several studies have demonstrated that in the mental health domain, experience does not always lead to better diagnostic decisions, suggesting that in clinical psychology experience-based intuition might actually not improve performance. The aim of the current study was to investigate differences in preferred reasoning styles of novice and experienced clinical psychologists as possible explanation of this surprising phenomenon. We investigated clinical and control decisions of novice (n = 20) and experienced (n = 20) clinical psychologists as well as age-matched controls (n = 20 and n = 20 respectively) by using vignettes and MouselabWeb matrices. We assessed their reasoning style preferences by using the Rational-Experiential Inventory (Pacini & Epstein, 1999). Results showed that experienced and novice clinical psychologists did not differ in diagnostic accuracy and that experienced psychologists had a higher preference for rational thinking than novices. We also found that in experienced psy- chologists a stronger preference for deliberation was associated with greater accuracy, and in novice psychologists a stronger preference for intuitive reasoning was associated with less accurate decisions. It might be that it is not a question of more experience but of deliberation about the task that could help clinicians perform more accurately.