Objective: Excessive salivation and drooling are distressing problems that affect both children and their families. Salivary gland botulinum toxin injection is a widely studied therapeutic method for treating sialorrhea. The proper protocol for such treatment modality is an area of interest for researchers. This study set out to assess the success of ultrasound-guided botulinum toxin injections in either the submandibular or combined with parotid salivary glands for children with cerebral palsy suffering from sialorrhea, while also identifying factors that predict a positive treatment outcome. Method: This cross-sectional study included 30 children with cerebral palsy who have Sialorrhea. Ultrasound-guided botulinum toxin injections of submandibular salivary glands alone or combined with parotid glands were done. Drooling was evaluated using Drooling Rating Scale, Drooling Impact Scale, and 5-minute Drooling Quotient. Children were followed up weekly for 12 weeks after botulinum toxin injections. Result: All children showed a significant decline in drooling and sufficient caregivers’ satisfaction for the first 8 weeks after botulinum toxin injections, with gradual worsening of drooling later in 60% of children. Assessment scores were significantly lower in those who received combined parotid and submandibular injections than those who received submandibular gland injections alone. Changes in drooling scores have a significant negative correlation with the severity of motor disabilities. Conclusion: Submandibular salivary gland injection alone has a satisfactory response in decreasing drooling in children with cerebral palsy. However, a combined injection of both parotid and submandibular salivary glands gives a better response for at least 8 weeks without complications. This study not only addresses the clinical effectiveness of botulinum toxin injections in managing sialorrhea in children with cerebral palsy but also opens avenues for improved dietary strategies. Keywords: botulinum toxin; salivary gland; sialorrhea; cerebral palsy