This article presents the four principle steps of assessment of children with cerebral palsy. Weakness of some muscles groups and spasticity of others and the subsequent functional impairment can be identified by observation. Analytical assessments of spasticity with the Ashworth and Tardieu scales were compared in 30 children with cerebral palsy, mean age 8.5 years. The results pointed out the complimentary nature of these two scales: The Gross Motor Function Measure, which is a validated scale, is specific for children with cerebral palsy. This measure provides a useful assessment of outcome and a convenient means of evaluating the time-course. Joint assessment is also essential to identify muscle contracture. Assessment of spasticity in children with cerebral palsy must be conducted by a multidisciplinary team to take into account all the aspects involved.