Background: Social communication disorder (SCD) is a neurodevelopmental disorder that includes communication difficulties. Literature linking SCD and addictions is scarce, and there are only a few case reports regarding the co-occurrence of addiction and autism disorder spectrum, and only one of them addressed behavioural addictions. Case presentation: We report MC?s case, who displayed an SCD and sexual addiction (SA). Clinical and neuropsychological evaluations suggested an alteration of social cognition, especially of affective theory of mind. This article also presents the adaptation made of the usual treatment. Discussion: This case report illustrates the importance of social cognition abilities in the development and maintenance of behavioural addictions, and specifically SA. It also highlights the possible comorbidity of these two disorders and the possibility to work on social cognition as an alternate therapy in the treatment of behavioural addictions. Conclusions: The co-occurrence of SCD and a behavioural addiction triggered clinical adaptations and implications that may affect a patient?s treatment presenting one of these disorders.  Kulcsszavak: social communication disorder, behavioural addiction, case report, sexual addiction, addictive disorder, neuropsychology