Kawasaki disease (KD) is an idiopathic vasculitis associated with systemic inflammation and profound immunoregulatory changes. Recent reports from Japan and the United States have documented the association of sensorineural hearing loss (SNHL) with acute KD. To further characterize the nature and prevalence of this complication, we prospectively evaluated the hearing of 40 consecutive patients with acute KD at a single institution. Standard audiometric procedures were used, including visual reinforcement audiometry and play audiometry. Auditory brainstem response (ABR) testing using clicks and tone pips (1000-4000 Hz) was performed in patients with abnormal or unreliable results on behavioral audiometry. Acoustic immittance measurements were obtained on all patients. Of the 23 males and 17 females (mean age 3.2 +/- 2.3 years, range 0.6-11.1 years), all but three were evaluated and treated with aspirin and intravenous gama globulin within 1 month of onset of fever. Seven children had test results suggesting sensorineural threshold shifts, 16 had normal hearing, and 14 had inconclusive hearing evaluations. Laboratory data in patients with hearing threshold shifts revealed significantly longer duration of fever (4.1 +/- 1.0 versus 1.9 +/- 0.5 days), and a tendency for higher temperatures and white blood cell counts at diagnosis compared to those with normal hearing. Results suggest that transient as well as persistent SNHL may be associated with the acute vasculitis of KD, and may be associated with laboratory markers indicating more severe systemic inflammation. Audiologic screening should be considered for all patients following KD.