BACKGROUND: One of the treatment option to reduce spasticity in cerebral palsy children is selective dorsal rhizotomy. Several studies have demonstrated short and long term improvements in gait and other activities after rhizotomy but this surgery still remains a controversial procedure and patient outcome indicators measures are not uniform. AIMS: To describe our assessment and outcome evaluation protocol and to verify by this protocol short term results of rhizotomy. METHODS: We recruited 9 cerebral palsy children (mean age 7.9 years ± 3.2) affected by mild to moderate spastic diplegia and operated by rhizotomy. Patients were studied preoperatively and at 12 months after surgery by the following clinical and instrumental measures correlated to the International Classification of Functioning: modified Ashworth Scale, passive Range of Motion, Medical Research Council Scale, Selective Motor Control Scale, 3D-motion analysis and energy cost of locomotion measurements (indicators of "body functions"); Gross Motor Functional Measure and Motor Functional Independence Measure (indicators of "activities and participation"). RESULTS: Our data showed, after rhizotomy, reduction of spasticity specially in plantarflexors muscles (p