The Pediatric RheumatologyWorking Group of the Portuguese Society of Rheumatology recommends the use of biological treatments in children with polyarticular course Juvenile Idiopathic Arthritis (JIA) with active disease (5 or more active joints) refractory to subcutaneous or intramuscular methotrexate (MTX) 15 mg/m(2)/week during 3 to 6 months. If toxicity occurs, or if there is contraindication for the use of MTX in this optimum dose, biological treatment can be started, as a first option, or the use of other conventional Disease ModifyingAnti Rheumatic Drug (DMARD) either alone or in combination with MTX might be considered. Prior to starting treatment, children should be screened for latent tuberculosis through clinical evaluation, chest X ray and PPD skin test. The suspension of the biological treatment should be considered if the American College of Rheumatology (ACR) definition of improvement in JIA is not fulfilled in two consecutive visits 3 months apart. Etanercept is the only biological agent currently approved for JIA in Portugal. In refractory cases the use of infliximab is accepted, in accordance with preliminary published evidence. In case of systemic manifestations of JIA refractory to conventional treatment, anakinra can be considered.