Background: Constraint-induced movement therapy (CIMT) is emerging as a treatment approach for children with hemiplegic cerebral palsy. It aims to increase spontaneous use of the affected upper limb and limit the effects of learned non-use. This review evaluates the effectiveness of CIMT, modified CIMT or Forced use in the treatment of children with hemiplegic cerebral palsy. Design and methods: Systematic Cochrane Review. The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 3), MEDLINE (1966 to August Week 4 2006), CINAHL (1982 to July Week 3 2006), EMBASE (1980 to August 2006), PsychInfo (1985 to August Week 4 2006) and reference lists of all relevant articles were searched. Relevant randomized and controlled clinical trials were systematically reviewed. Results: Three studies met the inclusion criteria. One randomized controlled trial (RCT) showed a trend for positive treatment effect favouring CIMT using the Dissociated Movement subscale of the Quality of Upper Extremity Skills Test. A clinically controlled trial demonstrated a significant treatment effect favouring modified CIMT using the Assisting Hand Assessment at two and six months. Another inconsistently reported trial showed a significant treatment effect at six weeks on the self-care component of the WeeFIM using Forced use. Reviewers' conclusions: Given the limited evidence, the use of CIMT, modified CIMT and Forced use should be considered experimental in children with hemiplegic cerebral palsy. Further research using adequately powered RCTs, rigorous methodology and valid, reliable outcome measures is essential to provide higher level support of the effectiveness of CIMT for children with hemiplegic cerebral palsy.