Impulsivity is inherent to both problem gambling and ADHD. The purpose of this study is to examine ADHD key symptoms, and gambling behaviors and problem severity among adolescents. Additionally, internalizing and externalizing behaviors exhibited among these individuals and the role of these symptoms in gambling are examined. We used a cross-sectional study design and survey 1,130 adolescents aged 12-19. Results indicated that adolescents who screened positive for ADHD were significantly more likely than non-ADHD adolescents to engage in gambling and significantly more likely to develop gambling problems. Those who screened positive as predominantly inattentive and those who screened positive for ADHD Combined (Inattention and Hyperactivity-Impulsivity) were equally likely to gamble, but the latter were twice as likely to have gambling problems. However, we found no significant interaction between the key ADHD symptoms and gambling as the severity of hyperactivity-impulsivity or inattention did not significantly differ with respect to gambling pathology. Emotional problems and depressive affect were the only variables that could significantly differentiate the ADHD types and gambling severity. Our Results highlight the clinical importance of considering the subtype of ADHD among gamblers and the greater association of depressive affect and emotional problems with gambling among adolescents.