Objective: Temperament and character is central to social behavioral development. It has been shown that various temperament and character dimensions are related with developmental pathologies in children and adolescents. It has been suggested that there is a complex and multi-dimensional interaction between attention deficit hyperactivity disorder (ADHD) and temperament and character. In this study it was aimed to investigate the relationship of the ADHD, a developmental psychopathology, with temperament and character properties in adolescence and young adulthood in a Turkish sample. Methods: The study included 37 adolescents and young adults of 17-22 years of age with the diagnosis of ADHD. The control group consisted of healthy individuals with no psychiatric disorder. The patients were assessed with Temperament and Character Inventory (TCI) following the diagnosis-oriented interview. Results: ADHD group had significantly higher points for novelty seeking, and significantly lower points for persistence, self-directedness, cooperativeness, and self-transcendence (p0.05). Conclusion: The results of this study in the direction of a higher novelty seeking detected in individuals with ADHD supports the literature on adults. Lower persistence, self-directedness, and cooperativeness properties, on the other hand, are consistent with previous literature on children and adolescents. The results of this study support the notion that certain temperament and character properties interact with ADHD. [Anadolu Psikiyatri Derg 2013; 14(4.000): 362-368]