Objective: In patients with cerebral palsy (CP), psychological problems influence their participation in society. Little is known about the persistence of behavioral and social problems into adulthood. Materials and methods: In a two-center cross-sectional study, caregivers of 121 adults and 88 children were ask to assess behavior of the patients through the parent/caregiver forms of the Child Behavior Checklist (CBCL), the Strengths and Difficulties Questionnaire (SDQ), and the Vineland Adaptive Behavior Scale II (VABS). Questionnaires were returned from 43 adults and 39 children. Results: In both groups we found the same frequency of abnormalities in attention problems (32.4 vs. 36.1%, p = 0.826) and social interaction problems (32.3 vs. 33.3%; p = 0.926) in the CBCL, and peer problems (38.9 vs. 75.7%; p = 0.115) in the SDQ. Children show a lower percentage of abnormal prosocial behavior (41.7 vs. 16.2%, p = 0.016) and lower abnormal rates of communication (88.2 vs. 61.5; p = 0.01) and daily living skills (90.0 vs. 71.8; p = 0.041), whereas the level of abnormalities in both groups in these dimensions of VABS notably high. Conclusion: The persistence of psychological and social problems from childhood into adulthood underlines the importance of focusing on early intervention. (C) 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.