Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder. Most common types, such as 21-hydroxylase and 11-beta-hydroxylase deficiency, lead to an increase in androgen synthesis. Elevated androgens contribute to the clinical manifestations of the disease. The antenatal and neonatal periods are critical for brain development, and exposure to testosterone during this time can influence various aspects, from gender differentiation to behavioral patterns. CAH is an essential disease for demonstrating the effects of hormones on human behavior. Individuals with CAH have reported impairments in different psychiatric disorders. It is well established that increased androgens during the antenatal period lead to virilization in the brain, shaping lifelong gender-related behaviors. The present chapter aims to provide a current summary of aggressive behavior and characteristics in individuals with CAH.