The Profile of Mood States (POMS) is commonly used to measure mental health in athletes. Athletes scoring below norms on scales of tension, depression, confusion, anger, and fatigue, and above norms on vigor, are said to possess a positive profile that graphically depicts an iceberg. However, the predictive power of the iceberg profile has recently been questioned. A meta-analysis was conducted on 33 studies comparing the POMS scores of athletes differing in success to estimate the magnitude of the findings. The overall effect size was calculated to be 0.15. Although this value was significantly different from zero, the amount of variance accounted for was less than 1%. The results suggest that across many different sports and levels of performance, successful athletes possess a mood profile slightly more positive than less successful athletes. However, with such a small and nonrobust effect, the utility of the POMS in predicting athletic success is questionable.