OBJECTIVE The Young Mania Rating Scale (YMRS) is the most widely used assessment tool for severity of manic symptoms in bipolar patients. While the original English version has been translated to various different languages, a validated German translation of YMRS has not yet been available. METHODS We translated the original English version to German (YMRS-D) and tested its use in clinical practice in 81 manic inpatients at two different psychiatric hospitals in Austria. The interviews were carried out by eight experienced and trained psychiatrists in random pairs of two interviewers. In order to assess concordance validity of YMRS-D, all patients were simultaneously rated using the Clinical Global Impression Rating Scale, Bipolar Version (CGIBP), by one of three experienced senior raters. RESULTS Inter-Rater Reliability was assessed calculating the Intra-Class Correlation Coefficient and showed high values (between 0.79 and 0.97, all p<.001) in all items of the German Rating Scale. Internal Consistency analysis of the scale yielded a value of .74 (Cronbach's Alpha). Spearmans rank correlation coefficient for the total scores of CGI-BP and YMRS-G was high (0.91, p<.001), suggesting good concordance validity of YMRS-D. Sensitivity to change was assessed in a subgroup of 20 patients by comparing YMRS-D and CGI-BP total scores at inclusion and at an additional interview three weeks later which showed a highly significant correlation (r = -0,953; p<.0005). CONCLUSIONS The German version of YMRS seems to be a valid, reliable and useful tool for the assessment and quantification of manic symptoms.