The importance of rhinosinusitis finally reached pediatricians' attention a few years ago, and it has now been demonstrated that it is medically important and has a considerable socioeconomic impact in childhood. These guidelines, which have been prepared with and approved by many Italian Scientific Societies, are based on the most recent findings in the fields of clinical symptoms, imaging and microbiology tests for the diagnosis of acute rhinosinusitis, and efficacy evidence concerning antibiotic treatment and non-antibiotic adjuvant treatment. A Pubmed search using the key words "sinusitis", "rhinosinusitis", "child" and "antibiotic treatment", and the limits "human studies" and "English language", led to the selection of more than 2,700 articles published between 1966 and 2007. These guidelines are based on the 125 that were considered truly relevant and reflect the most widely shared positions concerning the diagnosis and treatment of acute, subacute and recurrent rhinosinusitis in children.