Objective: Nicotine addiction is the most prevalent addiction type all over the world and attention deficit hyperac-tivity disorder (ADHD) is an important factor associated with nicotine addiction. Primary aim of this study was to evaluate the effect of ADHD symptoms on smoking cessation. Methods: Smokers who had admitted to the smoking cessation center were evaluated with using Wender Utah and Fagerstorm Scales at the beginning of study and for the success of smoking cessation at the end of 6 months. Results: Of the 353 smokers enrolled to the study, 99 individuals had a score of 36 or higher on Wender Utah scale (ADHD symptoms group). Of these 99 patients with ADHD symptoms, 11 (11.1%) and of the 254 non-ADHD symptoms group, 68 (26.8%) had quitted smoking after a period of six months. Logistic regression analysis revealed that having ADHD symptoms predicted failure of smoking cessation (adjusted odds ratios 2.12, 95% confidence interval 1.02-4.40) after controlling for sociode-mographic and smoking-related variables. Conclusions: ADHD symptoms may be an important factor affecting smoking cessation. Examining these symptoms in problematic nicotine addicts might help treatment outcome. [Anadolu Psikiyatri Derg 2016; 17(2.000): 104-110]