The development of new and more efficacious therapeutic agents, though expensive and potentially toxic, helped to implement objective measures to quantify the improvement and to monitor the evolution of inflammatory rheumatic diseases. The aim of our protocol (PMAIJ) is to supply rheumatologists and paediatricians with a useful tool for follow-up of juvenile arthritis patients using validated instruments for the evaluation of activity, functional capacity and response to treatment. PMAIJ has 2 pages. The first page is filled only at the initial evaluation; the second page is filled at first and in all the appointments after that. The application of this protocol would contribute to the standardization of procedures in different Paediatric Rheumatology Centres and would help to obtain useful information on the clinical evolution of JIA patients followed in Portugal.