We developed a secure, web-based system for parent-professional and inter-professional communication. The aim was to improve communication in the care of children with cerebral palsy. We conducted a six-month trial of the system in three Dutch health-care regions. The participants were the parents of 30 cerebral palsy patients and 120 professional staff involved in their care. Information about system usage was extracted from the system's database. The experience of the parents and professionals was evaluated by a questionnaire after six months. The system proved to be technically robust and reliable. A total of 21 parents (70%) and 66 professionals (55%) used the system. The parents submitted 111 questions and 59 responses, with a mean of 5 questions (range 1-17) and 3 responses (range 1-9) per parent. The professionals submitted 79 questions and 237 responses, with a mean of 2 questions (range 1-8) and 4 responses (range 1-23) per professional. Most parents (95%) and some professionals (30%) reported value in using the system, which ranged from efficiency and accessibility to flexibility and transparency. The web-based communication system was technically feasible and produced improved parent-professional and inter-professional communication. It may be especially valuable if frequent interventions or consultations about a child's care are required, involving complex care networks of different professionals and organisations.