The aim of this study was to develop and validate a shortened version of the Profile of Mood States suitable for use with adolescents. The Profile of Mood States-Adolescents (POMS-A) was administered to 1693 participants from two populations: school children and young athletes. Confirmatory factor analysis supported the factorial validity of a 24-item six-factor model using both independent and multi-sample analyses. Correlations of POMS-A scores with previously validated inventories, which were consistent with theoretical predictions, provided evidence of criterion validity. It is proposed that the POMS-A is a valid instrument for the assessment of mood in adolescents.