Objective: To present a case of pedophilic disorder associated to intellectual disability and substance-use disorder (SUD). Background: Pedophilic disorders often appear in comorbidity with other mental disorders. Case description: A 21-year-old man is hospitalized in an addictive behavior unit, with a history of SUD, an exclusive sexual preference for boys aged 12 or under, associated to interpersonal problems with borderline Intelligence Quotient score, and failure in global functioning. Discussion: The article analyses the criteria related to pedophilic disorder, the difficulties in its diagnosis, the clinical implications of the comorbidity with intellectual disability and SUD. Conclusions: It is important to differentiate between pedophilic disorder, SUD, and intellectual disability. An active search for deviant sexual behavior is recommended in patients with dual diagnosis.