Modified constraint-induced movement therapy (mCIMT) improves upper limb (UL) motor execution in unilateral cerebral palsy (uCP). As these children also show motor planning deficits, action-observation training (AOT) might be of additional value. Here, we investigated the combined value of AOT to mCIMT on UL kinematics in children with uCP. Thirty-six children with uCP completed an UL kinematic evaluation after participating in a 9-day mCIMT camp wearing a splint for 6 hours/day. The experimental group (mCIMT+AOT, n=20) received 15 hours of AOT, i.e. video-observation and execution of unimanual tasks. The control group (mCIMT+placebo, n=16) watched biological-motion free videos and executed the same tasks. We examined changes in motor control (movement duration, peak velocity, time-to-peak velocity, and trajectory straightness) and movement patterns (using Statistical Parametric Mapping) during the execution of three unimanual, relevant tasks before the intervention, after and at 6 months follow-up. Adding AOT to mCIMT mainly affected movement duration during reaching, whereas little benefit is seen on UL movement patterns. mCIMT, with or without AOT, improved peak velocity and trajectory straightness, and proximal movement patterns. These results highlight the importance of including kinematics in an UL evaluation to capture changes in motor control and movement patterns of the proximal joints.