Youth with Tourette syndrome (TS) often exhibit disruptive behaviors. Although improvement data on rating scales support the efficacy of structured psychotherapeutic interventions, there is growing interest in personalized outcome assessments. This report examined parent-nominated target problems (PTPs) as an individualized outcome measure in 48 youth with TS and disruptive behaviors, who participated in one of two randomized psychotherapy trials. At baseline, parents described two primary problems to an independent evaluator who generated a structured narrative for each problem. These narratives were reviewed and updated at endpoint. When rated by five treatment-blind judges, the PTP rating demonstrated excellent reliability and good convergent validity with the Disruptive Behavior Rating Scale (DBRS). The PTP rating exhibited comparable treatment effects to the DBRS, and accounted for additional variance in global treatment outcome. The PTP rating serves a reliable, valid, and sensitive personalized assessment in research trials that provides complementary information to standardized rating scales.