Background: Children with a physical disability are known to be at higher risk of an inactive life style. The hip, knee, and ankle joints have different roles depending on the phase of walking and running. They must work together to produce and absorb forces to allow efficient movement through the stance phase. In walking there are three rockers: the heel rocker, the ankle rocker, and the forefoot rocker. Objective: The aim of the study was to investigate the effect of ankle rocking training on the development of gross motor functional abilities in children with cerebral palsy. Patients and methods: Thirty children diagnosed as spastic cerebral palsy according to gross motor classification system, (Grade II & III GMFCs) were selected from the Outpatient Clinic, Faculty of Physical Therapy, Cairo University. The children' ages ranged from three to six years old from both sexes. This was a cross-sectional study where the selected cerebral palsied children were divided into two groups (control group and study group). The control group received traditional gait training and standing program, while the study group received the same traditional gait training and standing program in addition to gait training using ankle rocker device. Both groups received treatment program 3 times/week for three consecutive months for one hour per session. Results: It was revealed that there was a significance difference within each single group (the pre- and post-treatment) and between both groups. Conclusion: According to the current study results, there was a highly significant difference within the study group pre- and post-treatment and between groups in favour of the study group because of ankle rocking training.