The cross-cultural validity of the Outcome Questionnaire (OQ) in the Dutch population has been examined by comparing the psychometric properties and equivalence in factor structure and normative scores of the Dutch OQ with the original American version. Data were collected from a university (n = 268), in a community (n = 810) and from three mental health care organizations (n = 1920). Results show that the psychometric properties of the Dutch OQ were adequate and similar to the original instrument. Some differences in equivalence were found though. In factor analysis, two additional factors were found: one consisting of social role items and another that reflected anxiety and somatic symptoms. Furthermore, normative scores were different for the Dutch and American samples, and this resulted in different cut-off scores for estimating a clinically significant change in the Dutch population. Copyright © 2007 John Wiley & Sons, Ltd.