We compared population-based prevalence rates of unilateral hearing loss among African-American, Cuban-American, Mexican-American, Puerto Rican, and non-Hispanic White children 6 to 19 yr of age. The prevalence (per thousand) of overall hearing loss (average decibel HTL >30) ranged from 6.4 in Mexican-Americans to 12.3 in Cuban-Americans. The prevalence of moderate to profound unilateral hearing loss (average decibel HTL >50) ranged from 0.0 in Cuban-Americans to 5.2 in Puerto Ricans. No statistically significant age or gender differences were found within any of the ethnic groups. Among these five ethnic groups, it is estimated that approximately 391,000 school-aged children in the United States have unilateral hearing loss.