The purpose of this review was to examine the effectiveness of botulinum toxin injections to the upper and lower extremities reported in studies of pediatric participants with severe cerebral palsy on improving ease of care, pain, and motor function. PubMed, CINAHL, and Web of Science were searched using combinations of cerebral palsy and various types and abbreviations of botulinum toxin. Additionally, reference lists and citations of reviewed studies were searched. The results of 25 studies were reviewed: three randomized controlled trials (RCTs) and 22 nonrandomized studies of interventions involving only a botulinum toxin-treated group. Seven studies focused solely on the targeted population while the remainder included participants of a wider range of severity. Ease of care was generally reported as improved. The effect on pain was variable: postoperative pain was significantly reduced in one RCT but not in another; nonspecific pain was improved in some cases; and joint specific pain was decreased in one study. Motor function changes were the most frequently evaluated in the studies without a comparison group; however, only a few used standardized assessment tools, e.g., Gross Motor Function Measure, and found pre- to postinjection improvement. The described findings need to be viewed cautiously due to the low level of rigorousness of most of the reviewed studies.