The entity of hindbrain herniation without myelodysplasia in the very young child has been poorly described. A retrospective analysis of children diagnosed with Chiari I malformation (CM I) before their sixth birthday is presented. Since 1985, 31 children with CM I (0.3-5.8) years of age have been diagnosed at University of Iowa Hospitals and Clinics. Their records were reviewed for presenting symptoms, signs, radiographic findings, treatment, complications, and outcome. The average age at diagnosis was 3.3 years. Sixteen patients were under age 3. Chief presenting complaints included impaired oropharyngeal function (35%), scoliosis (23%), headache or neck pain (23%), sensory disturbance (6%), weakness (3%), and other (10%). Sixty-nine percent of children under age 3 had abnormal oropharyngeal function. Three patients under age 3 (19%) had undergone fundoplication and/or gastrostomy before diagnosis of CM I. Common physical findings included abnormal tendon reflexes (68%), scoliosis (26%), abnormal gag reflex (13%), and normal examination (13%). Vocal cord dysfunction (26%, all under age 3) and syringohydromyelia (52%) were also seen. Twenty-five patients were treated surgically at our institution with posterior fossa decompression, duraplasty, and cerebellar tonsillar shrinkage. Three patients were lost to follow-up. Ninety-one percent of patients reported improved symptomatology at last follow-up (mean: 3.9 years). Three patients required reoperation for recurrence of symptoms. Syringomyelia improved in all patients. Scoliosis resolved in 2 of 8 patients, improved in 5, and stabilized in 1. There was no permanent morbidity from surgery. We show that children with Chiari I abnormality are very likely to present with oropharyngeal dysfunction if under age 3, and either scoliosis or headache or neck pain worsened by valsalva if age 3 to 5. These symptoms are very likely to improve after Chiari decompression, which can be done with low morbidity. Very young children presenting with oropharyngeal dysfunction, pain worsened by valsalva, or scoliosis should prompt the clinician to consider CM I as a possible cause.