This study isolates the voice problems of 99 (40 male, 59 female) children choir singers (age range: 8–14), by applying and validating a simple method for classifying the singing voice. The prevalence of dysphonia was 20.2%. A singing range of fewer than 18 semitones is considered to suggest dysphonia (sensitivity of 80% and specificity of 95%). The validity of the method and its ease of application are discussed. We conclude that voice classification is necessary for all children who sing and that phoniatric examination of dysphonic children is imperative, with special attention given to those whose voices are changin