Episodes of explosive anger and aggression are reported in patients with tic disorders and probably contribute to psychosocial stress and low quality of life. The source of these symptoms is controversial. The objective of the study was to study the relationship between tic disorders, their associated comorbidities, and aggressive behavior. The cohort included 47 children and adolescents (age 7-17 years) with Tourette syndrome or other chronic tic disorders attending a tertiary pediatric Tourette clinic. Associated psychopathology was assessed with the Yale Global Tic Severity Scale, Yale Brown Obsessive Compulsive Scale, Conners ADHD Rating Scale, Screen for Child Anxiety-Related Emotional Disorders, and Child Depression Inventory. Aggression was assessed with the Overt Aggression Scale and scores were compared with a group of 32 healthy age- and sex-matched children. There were no significant differences in aggression scores between the children with tic disorders and controls. Verbal aggression was the most prevalent type of aggression, found in 70% of the patients with tic disorders. The level of aggression was not correlated to tic severity. Comorbid attention-deficit hyperactivity disorder and obsessive-compulsive disorder increased the probability of aggressive behavior in patients with tic disorders. On regression analysis, the only significant predictor of aggression was the severity of attention-deficit hyperactivity disorder. This study suggests that there is no difference in aggressive behavior between children with tics without comorbidities and healthy children. It is possible that aggressive behavior in children with tic disorders is predominantly associated with comorbid attention-deficit hyperactivity disorder.