Adolescence is a critical period of life during which significant psychosocial adjustment occurs and in which emotional intelligence plays an essential role. This article provides validity evidence for the Trait Meta-Mood Scale-24 (TMMS-24) scores based on an item response theory (IRT) approach. A sample of 2,693 Spanish adolescents (M = 16.52 years and SD = 1.38), of whom 51.1% were boys, completed the TMMS-24. The three-dimensional structure of the TMMS-24 was confirmed, showing adequate psychometric properties for assessing adolescents. With one exception, the IRT analyses showed that the items have a reasonable fit to Samejima's Gradual Response Model. In addition, all three dimensions exhibit the best measurement precision around the mean of the latent trait levels. Again, with one exception (Item 23), all items have a moderate to very high discrimination power.