This research was designed to provide a socially valid evaluation of the posttreatment speech of children who received an operant treatment for early stuttering (The Lidcombe Program). Part A compared the posttreatment percent syllables stuttered (%SS) for preschool and school-age children with nonstuttering control children matched for age and sex. This study found that both groups attracted similar measures of %SS. Part B compared the number of "stuttering" versus "not stuttering" judgments made by experienced clinicians and unsophisticated listeners on the same speech samples. Control children were identified as "stuttering" significantly more than the treated children. The clinician listeners identified significantly more control samples and posttreatment samples as stuttering than the unsophisticated listeners. The implications of these results are discussed. It is concluded that The Lidcombe Program resulted in socially valid modifications in the participant's speech.