The purpose of this study was to perform an initial validation of a Swedish translation of the Clinical Outcomes in Routine Evaluation Outcome Measure (CORE‐OM). The CORE‐OM is a broad self‐report instrument of psychological problems, designed as an outcome measure for evaluating the effects of psychological therapy. Participants included a non‐clinical group of 229 university students and a clinical group of 619 persons from four primary care sites. The Swedish CORE‐OM showed excellent acceptability, high internal consistency and test–retest reliability, as well as acceptable convergent validity. There was strong differentiation of the clinical and non‐clinical samples, with the clinical group scoring significantly more psychological problems than the non‐clinical group. Sensitivity to change was demonstrated in psychological treatments in primary care. Overall, the psychometric characteristics of the Swedish CORE‐OM were very similar to the original UK data. Nevertheless, the validity of the Swedish version needs to be examined more in detail, in larger and more diverse samples. Our results so far, however, provide support for using the Swedish CORE‐OM as a psychological problems measure. To our knowledge, there are few other relatively short measures in Swedish that are free to reprint that meet the demands for psychometric properties and utility in primary care settings in which patients typically present a broad range of psychological problems. Copyright © 2012 John Wiley & Sons, Ltd.Key Practitioner MessageThe Swedish version of the CORE‐OM is a valid questionnaire for assessing the severity of a broad range of psychological problems.