In adult-onset multiple sclerosis (MS) cases, major depression, fatigue and psychological distress are common, whereas there is little information on these issues in children with the disease. The aim of this study was to assess psychosocial disorders in an Italian cohort of children and adolescent with MS. We evaluated 56 patients through self-assessment scales of depression (Children Depression Inventory) and fatigue (Fatigue Severity Scale), a psychiatric interview [Kiddie-SADS-Present and Lifetime Version (K-SADS-PL)] and an interview on school and everyday activities. Significant fatigue was found in 11 patients (20%). Twelve of the 39 patients who underwent the K-SADS-PL received a formal diagnosis of an affective disorder. Moreover, MS affected school activities in 28% of cases, daily living activities in 41% and social relationships in 28%. Our study confirms the critical role of psychosocial difficulties in children and adolescents with MS and provides a few cues to clinical management.