Marshall's syndrome or PFAPA (periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis) syndrome is a recently described pediatric periodic disease characterized by recurrent febrile episodes associated with head and neck symptoms. The origin of this syndrome is unknown, and it can last for several years. During healthy periods, patients grow normally. The differential diagnosis includes other diseases characterized by periodic fevers, such as familial Mediterranean fever, familial Hibernian fever, hyperglobulinemia D syndrome, Behçet's disease, cyclic neutropenia, juvenile rheumatoid arthritis, and several infectious diseases. Many treatments have been used, with various results, including antibiotics, nonsteroidal anti-inflammatory drugs, acetylsalicylic acid, colchicine, antiviral medicines, steroids, cimetidine, and tonsillectomy. We describe 5 new patients affected by PFAPA syndrome who were observed at the Department of Pediatric Otorhinolaryngology, Spedali Civili, Brescia, Italy, from November 2000 to August 2001. All children underwent physical examination, bacterial, fungal, and viral cultures, chest radiography, and several laboratory studies. The patients were treated by successful tonsillectomy, and after a mean follow-up of 10 months, no recurrence was observed. An analysis of the literature is also presented with particular emphasis on the differential diagnosis of this rare illness and the results of the different therapeutic options.