PURPOSE: The purpose of this study was to evaluate anxiety and psychological functioning among adolescents seeking speech therapy for stuttering using a structured, diagnostic interview and psychological questionnaires. This study also sought to determine whether any differences in psychological status were evident between younger and older adolescents. METHOD: Participants were 37 stuttering adolescents seeking stuttering treatment. We administered the Computerized Voice Version of the Diagnostic Interview Schedule for Children, and five psychometric tests. Participants were classified into younger (12-14 years; n=20) and older adolescents (15-17 years; n=17). RESULTS: Thirty-eight percent of participants attained at least one diagnosis of a mental disorder, according to the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; APA, 2000), with the majority of these diagnoses involving anxiety. This figure is double current estimates for general adolescent populations, and is consistent with our finding of moderate and moderate-severe quality of life impairment. Although many of the scores on psychological measures fell within the normal range, older adolescents (15-17 years) reported significantly higher anxiety, depression, reactions to stuttering, and emotional/behavioral problems, than younger adolescents (12-14 years). There was scant evidence that self-reported stuttering severity is correlated with mental health issues. There are good reasons to believe these results are conservative because many participants gave socially desirable responses about their mental health status. DISCUSSION: These results reveal a need for large-scale, statistically powerful assessments of anxiety and other mental disorders among stuttering adolescents with reference to control populations. EDUCATIONAL OBJECTIVES: The reader will be able to: (a) explain the clinical importance of assessing for mental health with stuttering adolescents, (b) state the superior method for adolescent mental health assessment and (c) state a major issue with determining the genuineness of stuttering adolescent responses to psychological assessment.