The purpose of this article was to describe a child-friendly modified constraint-induced movement therapy protocol that is combined with goal-directed task-specific bimanual training (mCIMT-BiT). This detailed description elucidates the approach and supports various research reports. This protocol is used in a Pirate play group setting and aims to extend bimanual skills in play and self-care activities for children with cerebral palsy and unilateral spastic paresis of the upper limb. To illustrate the content and course of treatment and its effect, a case report of a two-year-old boy is presented. After the eight-week mCIMT-BiT intervention, the child improved the capacity of his affected arm and hand in both quantitative and qualitative terms and his bimanual performance in daily life as assessed by the Assisting Hand Assessment, ABILHAND-Kids, Video Observations Aarts and Aarts Module Determine Developmental Disregard, Canadian Occupational Performance Measure and Goal Attainment Scaling. It is argued that improvement of affected upper-limb capacity in a test situation may be achieved and retained relatively easily, but it may take a lot more training to stabilize the results and automate motor control of the upper limb. Future studies with groups of children should elaborate on these intensity and generalization issues.