Objective: Prior research has long emphasized the role of alexithymia and impulsivity to explain aggressive tendencies. Recently, a growing body of research seems to support the relevance of the broader construct of emotion dysregulation to understand aggression. The present study was the first to comprehensively examine the relative contribution of, and the mechanisms linking alexithymia, impulsivity, and emotion dysregulation in predicting aggression dimensions. Method: Male violent offenders (N = 221) and community participants (N = 245) completed multifaceted self-report measures of alexithymia, impulsivity, emotion dysregulation, and aggression. Regression analyses tested the independent contribution of each facet on aggression dimensions. Bootstrap analyses examined the indirect effect of alexithymia on aggression through emotion dysregulation and impulsivity. Results: Offenders reported higher levels of difficulties identifying feelings, emotional nonacceptance, physical aggression, and hostility. Difficulties in identifying and describing feelings, and motor and attentional impulsivity, explained unique variance in physical aggression, anger, and hostility in both samples, and also in verbal aggression among community participants. In both samples, negative urgency and emotional nonacceptance explained additional variance in aggression dimensions above and beyond the influence of alexithymia and impulsivity. Emotion dysregulation and impulsivity mediated the relation between alexithymia and aggression in both samples, with emotion dysregulation demonstrating a relatively stronger effect. Conclusions: Findings emphasize the unique relevance of alexithymia, impulsivity, and emotion dysregulation facets in explaining aggressive tendencies. Clinical implications include the importance of focusing on emotion regulation skills—such as accepting emotions and do not act on them—to reduce aggression tendencies.