BackgroundNovel neurorehabilitation technologies build upon treatment principles derived from motor learning studies. However, few studies have investigated motor learning with assistive devices in children and adolescents with Cerebral Palsy (CP). The aim of this study was to investigate whether children with CP who trained with weight support in a playful, virtual environment would improve upper extremity task performance (i.e. skill acquisition), transfer, and retention, three aspects that indicate whether motor learning might have occurred or not.MethodsEleven children with CP (mean age 13.3 years, standard deviation 3.4 years), who were mildly to moderately impaired, participated. They played in the Armeo® Spring the exergame Moorhuhn with their more affected arm during 3 days (70 min pure play time). For this within-subject design, kinematic assessments, the Box and Block Test, and five items of the Melbourne Assessment were administered twice during a baseline week (one week before the intervention), directly before and after the intervention, and one day after the training phase (retention).ResultsThe average exergame score improved from 209.55 to 339.73 (p < 0.001, Cohen’s d = 1.80), indicating skill acquisition. The change in the Box and Block test improved from 0.45 (baseline week) to 3.95 (intervention week; p = 0.008, d = 1.59) indicating skill transfer. The kinematic assessments and the Melbourne items did not change. Improvement in game score and Box and Bock Test persisted one day later (retention).ConclusionsWe found evidence indicating the successful acquisition, transfer, and retention of upper extremity skills in children with CP. We therefore infer that motor learning occurred when children with CP trained their more affected arm with weight-support in a playful, virtual environment.