Aims: The behavioural-addiction perspective suggests that Internet addiction (IA) and pathological gambling (PG) could share similar characteristics with substance dependence. Despite the similarities between IA and PG, it is not clear whether these disorders share different or similar psychopathological conditions. The aim of the present study was to test whether IA patients presented different psychological symptoms, temperamental traits, coping strategies and relational patterns compared with PG patients. The hypothesis was that IA patients will show greater interpersonal disengagement than PG patients. Methods: Two clinical groups (31 IA patients and 11 PG patients) and a control group (38 healthy subjects) matched with the clinical groups for gender and age were enrolled. The clinical groups were gathered in a psychiatric service for IA and PG in a hospital. Anxiety, depression, coping strategies, attachment, temperament, and global assessment of functioning were measured. MANOVAs, ANOVAs and post-hoc comparisons were carried out in order to test the hypothesis. Results: Despite IA and PG showing similar differences with the control group on the levels of depression, anxiety and global functioning, the two clinical groups showed different temperamental, coping and social patterns. Specifically IA patients compared with the PG patients showed a greater mental and behavioural disengagement associated with an important interpersonal impairment. The two clinical groups shared an impulsive coping strategy and socio-emotional impairments. Conclusions: Despite IA and PG patients presenting similar clinical symptoms, IA condition was characterised by a more relevant mental, behavioural, and social disengagement compared to PG condition.