Background: Although the correlation between substance use disorder and attention deficit hyperactivity disorder (ADHD) has been largely studied, less is known about the correlation between behavioral addictions and ADHD. Thus, the aim of the present study was to investigate the prevalence of behavioral addictions in a large sample of adult patients with a primary diagnosis of ADHD and to compare the clinical profile of ADHD patients with and without behavioral addictions comorbidity. Methods: 248 consecutive adults newly diagnosed as ADHD patients were assessed through a series of validated scales for gambling disorder, internet, sex, shopping and food addictions. ADHD patients with at least one comorbid behavioral addiction were compared to non-comorbid patients on ADHD symptoms, impulsivity, mood and anxiety symptoms and functional impairment. Results: 58.9% of patients had at least one behavioral addiction comorbidity. Of the whole sample, 31.9% of the patients had a comorbidity with one behavioral addiction while the 27% showed a comorbidity with two or more behavioral addictions. Internet addiction was the most common comorbidity (33.9%) followed by food addiction (28.6%), shopping addiction (19%), sex addiction (12.9%) and gambling disorder (3.6%). ADHD patients with comorbid behavioral addictions showed higher ADHD current and childhood symptoms, higher cognitive and motor impulsivity, higher mood and anxiety symptoms and higher functional impairment. Conclusions: Behavioral addictions are highly frequent in adult ADHD patients. Comorbid patients seem to have a more complex phenotype characterized by more severe ADHD, mood and anxiety symptoms, higher impulsivity levels and greater functional impairment.  Kulcsszavak: ADHD, internet addiction, gambling disorder, shopping addiction, food addiction, sex addiction, impulsivity, mood and anxiety symptoms