The clinical practice guideline on otitis media with effusion (OME) provides evidence-based recommendations on diagnosing and managing OME in children. This is an update of the 1994 clinical practice guideline "Otitis Media With Effusion in Young Children," which was developed by the Agency for Healthcare Policy and Research (now the Agency for Healthcare Research and Quality). In contrast to the earlier guideline, which was limited to children aged 1 to 3 years with no craniofacial or neurologic abnormalities or sensory deficits, the updated guideline applies to children aged 2 months through 12 years with or without developmental disabilities or underlying conditions that predispose to OME and its sequelae. The American Academy of Pediatrics, American Academy of Family Physicians, and American Academy of Otolaryngology-Head and Neck Surgery selected a subcommittee composed of experts in the fields of primary care, otolaryngology, infectious diseases, epidemiology, hearing, speech and language, and advanced practice nursing to revise the OME guideline. The subcommittee made a strong recommendation that clinicians use pneumatic otoscopy as the primary diagnostic method and distinguish OME from acute otitis media (AOM). The subcommittee made recommendations that clinicians should (1) document the laterality, duration of effusion, and presence and severity of associated symptoms at each assessment of the child with OME; (2) distinguish the child with OME who is at risk for speech, language, or learning problems from other children with OME and more promptly evaluate hearing, speech, language, and need for intervention in children at risk; and (3) manage the child with OME who is not at risk with watchful waiting for 3 months from the date of effusion onset (if known), or from the date of diagnosis (if onset is unknown). The subcommittee also made recommendations that (4) hearing testing be conducted when OME persists for 3 months or longer, or at any time that language delay, learning problems, or a significant hearing loss is suspected in a child with OME; (5) children with persistent OME who are not at risk should be reexamined at 3- to 6-month intervals until the effusion is no longer present, significant hearing loss is identified, or structural abnormalities of the eardrum or middle ear are suspected; and (6) when a child becomes a surgical candidate, tympanostomy tube insertion is the preferred initial procedure. Adenoidectomy should not be performed unless a distinct indication exists (nasal obstruction, chronic adenoiditis); repeat surgery consists of adenoidectomy plus myringotomy, with or without tube insertion. Tonsillectomy alone or myringotomy alone should not be used to treat OME. The subcommittee made negative recommendations that (1) population-based screening programs for OME not be performed in healthy, asymptomatic children and (2) antihistamines and decongestants are ineffective for OME and should not be used for treatment; antimicrobials and corticosteroids do not have long-term efficacy and sh...