In this study, we investigated the hypothesis that autistic traits associated with alexithymia, when related to aggressiveness, relate to aggressive behavior. For the purpose of this study, 208 students voluntarily participated in the experiment. Their autistic traits were measured using the Autism-Spectrum Quotient, their aggressiveness was examined using the Buss-Perry Aggression Questionnaire and the Implicit Association Test, and alexithymia traits were estimated using the 20-item Toronto Alexithymia Scale, while aggressive behavior was assessed using the Aggressive Behavior Scale and by measuring the intensity of unpleasant noise. The results revealed that all subscales of the autism traits have a positive relationship with the alexithymia traits. The results of covariance structure analysis revealed that participants’ difficulty performing attention switching and focusing on small details was related to aggressiveness and was thus positively related to aggressive behavior. In addition, poor communication was directly and positively related to aggressive behavior, while poor social skills were directly and negatively related to aggressive behavior. However, poor imagination did not relate to aggressiveness and aggressive behavior. The coefficient alpha of focusing on local details and poor imagination was low. The relation between autistic traits and aggressive behavior was then discussed.