Objective The purpose of the Nordic Long-Term OCD Treatment Study (NordLOTS) was toexamine the acute effectiveness of manualizedexposure-based Cognitive Behavioral Therapy (CBT) asan initial treatment for pediatric Obsessive-CompulsiveDisorder (OCD). Also, to investigate the effectivenessof sertraline (SRT) versus continued CBT in childrenand adolescents who did not respond to the initial courseof CBT. Finally, to describe the 1-year treatmentoutcome of the initial CBT responders. Method Thestudy included 269 participants, age 7-17, diagnosedwith OCD according to DSM-IV. In step I, all receivedCBT for 14 weekly sessions. In step II, 54 nonrespondersto CBT were randomized to SRT orcontinued CBT for 16 weeks. Treatment response wasin all cases defined as a Children’s Yale-BrownObsessive-Compulsive Scale (CY-BOCS) score of =15at post treatment. The 177 responders to CBT from stepI were assessed with the CY-BOCS at 6- and 12-monthfollow-up. Results In step I, 241 participants (89.6%)completed all 14 weeks of treatment with a treatmentresponse of 72.6% (95% CI: 66.7%-77.9%) and a meansymptom reduction on the CY-BOCS of 52.9% (SD =30.9). In step II, 21 of 28 participants (75 %) completedcontinued CBT, and 15 of 22 participants (69.2 %)completed SRT treatment. The response rate was 50.0 %in the CBT group and 45.4 % in the SRT group.Comparison of the CY-BOCS total score did not reveala significant difference between the treatment types (p =0.351). At 1-year follow-up of step I CBT responders(n=177), a total of 155 (87.6%) were available forassessment, with 142 (91.6%) still rated as responders.On average, the CY-BOCS total scores dropped by 1.72points during the first year after terminating step I CBT(p = 0.001). Conclusion This study found that CBT canbe applied effectively in community mental healthclinics and that that CBT non-responders are equallylikely to benefit from either continued CBT or treatmentwith SSRI. CBT for pediatric OCD is shown to havedurable effects for those who respond to an initial courseof CBT.