Emotion regulation (ER) is a crucial construct in the study of child education, development, and psychopathology. The How I Feel (HIF) questionnaire, a self-report measure of ER for children, was validated in school-based, nonclinical samples. The current study examined the factor structure of the HIF in a clinical sample of children (N = 195; 73.33% male; 79.49% White; 61.03% diagnosed with ADHD). Confirmatory factor analysis did not support the original 3-factor model. An exploratory factor analysis revealed an altered five-factor model with identical Positive Emotion and Emotion Control factors, but the original Negative Emotion factor was divided into three factors: Mad Emotion, Sad and Scared Frequency, and Sad and Scared Intensity. Results suggest that the HIF may not accurately assess the intensity and frequency of negative emotions in clinical samples.