BACKGROUND: Cerebral palsy (CP) is a central nervous system deficit resulting from a non-progressive lesion in the developing brain. Although the brain lesions are static, the movement disorders that arise are not unchanging and are characterised by atypical muscle tone, posture and movement (Rang 1990). The spastic motor type is the most common form of CP and its conventional therapeutic management may include splinting/casting, passive stretching, facilitation of posture and movement, spasticity-reducing medication and surgery. More recently, health care professionals have begun to use botulinum toxin A (BtA) as an adjunct to interventions in an attempt to reduce muscle tone and spasticity to improve function OBJECTIVES: To assess the effectiveness of intramuscular BtA injections as an adjunct to managing the upper limb in children with spastic CP. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2003), MEDLINE (1966 to March Week 3 2004), EMBASE (1980 to 2003 Week 16) and CINAHL (1982 to Week 3 March 2004). SELECTION CRITERIA: All randomised controlled trials (RCTs) comparing intramuscular BtA injections into any muscle group of the upper limb with placebo, no treatment or other interventions. DATA COLLECTION AND ANALYSIS: Two authors using standardised forms extracted the data independently. Each trial was assessed for internal validity with differences resolved by discussion. Data was extracted and entered into RevMan 4.2.3. MAIN RESULTS: Two trials met the inclusion criteria, each having short-term follow up, a small number of subjects and using a single set of injections. The study by Corry 1997 compared BtA with an injection of normal saline and found promising results in elbow extension, elbow and wrist muscle tone. At three months, encouraging results for wrist muscle tone and grasp and release were noted. The trial reported median change, range of changes and the difference in these measures between groups. The study by Fehlings 2000 compared BtA with no intervention. When data were analysed no treatment effect was found for quality of upper limb function, passive range of motion, muscle tone, grip strength or self-care ability. REVIEWERS' CONCLUSIONS: This systematic review has not found sufficient evidence to support or refute the use of intramuscular injections of BtA as an adjunct to managing the upper limb in children with spastic cerebral palsy. Only one of the two identified RCTs reported some promising results in support of reduced muscle tone following BtA injections. Further research incorporating larger sample sizes, rigorous methodology, measurement of upper limb function and functional outcomes is essential.