Cerebral palsy is leading cause of physical disability in childhood. This interferes with normal ambulation. Rectus femoris muscle spasticity has been reported to be a cause of stiff knee gait in the patients with cerebral palsy. This study aimed to analyse changes in sagittal knee joint kinematic parameters following botulinum toxin injection to the rectus femoris. Fifteen patients were included in the study. A Vicon Motion capture system with Plug-in-Gait model was used for the pre- and post-treatment gait analysis of knee joint angles as well as knee joint flexion velocity. The results from statistical analysis revealed that there were no significant differences in the knee joint range of motion as well as velocity of knee joint flexion in the pre-swing and early swing phase of gait cycle. Although statistical results did not show any significant improvement, it was noted that there was variation in the outcomes for individual patients, with some showing improvements.