In the management of adults with cerebral palsy (CP), one of the goals is to monitor and prevent spasticity-related deteriorations in gait. Botulinum Toxin Injections (BTI) are commonly used to treat this spasticity in these patients. The purpose of this study was to evaluate (i) the effect of multi-site BTI on gait patterns in adults with CP and (ii) to determine if these modifications could be detected by the Gait Deviation Index (GDI).