Recent reviews argue that emotion dysregulation is an important feature of attention-deficit/hyperactivity disorder (ADHD) and involves a failure to inhibit negative emotions that leads to negative affectively-driven impulsive behavior (i.e., emotional impulsivity). The goal of the current study was to assess (a) whether emotion dysregulation and emotional impulsivity was higher in a group of adults diagnosed with ADHD and (b) if the relationship between core ADHD symptoms (i.e., inattention and hyperactivity-impulsivity) and emotional impulsivity is mediated by emotion dysregulation symptoms. A group of adults with (n = 18) and without (n = 23) ADHD completed measures of core ADHD symptoms, emotion dysregulation, and emotional impulsivity. A series of one-way analyses of covariance indicated significant between-group differences in emotion dysregulation and emotional impulsivity when current depression and oppositional defiant disorder ratings were covaried. In addition, the relationship between ADHD symptoms and emotional impulsivity was mediated by emotion dysregulation symptoms. These findings suggest that emotion dysregulation and emotional impulsivity are higher in adults diagnosed with ADHD and that emotion dysregulation symptoms have predictive value beyond core ADHD symptoms.