Respiratory syncytial virus (RSV) infects about 15% to 20% of all children younger than 2 years and in the major part of cases results in mild upper respiratory tract disease with a spontaneous resolution, but in a minority (usually infants <6 months old), it causes serious respiratory tract disease. However, in some high-risk pediatric groups (preterm infants, particularly with a gestational age younger than 32 weeks, children with lung disease or affected by pulmonary or cardiac disease and in immunocompromised children), severe lower respiratory tract infection with considerable illness and death is a more frequent occurrence. Palivizumab, a genetically engineered humanized monoclonal antibody, has been shown to reduce RSV-related hospitalizations significantly, with few adverse effects. It was approved for use in high-risk children in the USA in 1998 and in Europe in 1999; it is now approved for use in more than 45 countries. The aim of this review is to evaluate the efficacy and tolerance of this drug in the prevention of RSV infection.