Objective: This proof-of-concept feasibility trial examined the potential of the Cognitive Orientation to daily Occupational Performance (CO-OP) ApproachTM to augment deep brain stimulation (DBS) outcomes in childhood-onset hyperkinetic movement disorders (HMD) including dystonia and dyskinetic cerebral palsy. Methods: Single case experimental design using multiple baseline as N-of-1 trial comprised of 10 intervention sessions, with replications across participants (n=10). Treatment focused on three participant-selected goals. Transfer was assessed on two additional untreated goals. Individuals enrolled were 6-21 years of age, had DBS in situ and sufficient manual ability. Primary outcome was functional performance change on the Performance Quality Rating Scale-Individualized (PQRS-i) measured before, during, post-treatment, and at 3-months follow-up. Assessors of outcome were blinded to time of assessment, number of intervention session and treatment allocation. To measure effect size, a non-overlapping index, Tau-U, was used. Feasibility parameters were captured. Results: One participant withdrew before baseline assessment. Effect sizes of at least 0.66 were seen at both post-treatment and follow-up with all participants showing improvements in at least one trained goal in PQRS-i. Six participants improved on all three goals and two improved on two trained goals. Two children showed deterioration in one trained goal each. Transfer to untrained goals was observed in three participants for a total of five goals. CO-OP was feasible and acceptable to all participants. Conclusion: A cognitive-based, task-oriented approach to support performance of personally relevant functional skills enabling participation is acceptable in childhood-onset HMD post-DBS. Further, preliminary efficacy to improve outcomes and proof of concept with CO-OP has been established in this population. Classification of Evidence: This study provides Class III evidence that for children with hyperkinetic movement disorders who had undergone DBS, CO-OP improves performance of personally relevant functional skills.