Objective: We aimed to evaluate treatment response in children with sluggish cognitive tempo and attention deficit/ hyperactivity disorder. Method: Child Behavior Checklist and Barkley Child Attention Scale were used to define SCT symptoms. Parents and teachers completed Turgay DSM-IV-Based Screening Scale for Disruptive Behavior disorders, severity and improvement were eva-luated via Clinical Global Impressions Scale- Severity and CGI- Improvement. Methylphenidate responses were evaluated retrospectively by patient charts. Results: SCT + ADHD group was rated as more inattentive by their parents while teachers rated children with ADHD as more hyperactive/ impulsive (p<0,01; p<0,01, respectively). Symptom reduction was significantly greater for teacher rated hyperactivity/ impulsivity in the ADHD group and children with SCT+ ADHD were still rated as more inattentive by their parents after treatment. The sole predictor of treatment response in the SCT+ ADHD group was treatment duration (p=0.012). Discussion: Longer treatment duration seemed to be more effective in the SCT group.