BACKGROUND: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired immune-mediated inflammatory disorder that targets the myelin sheaths of the peripheral nervous system. Intravenous immunoglobulin (IVIg) is a blood product containing immunoglobulin G (IgG) that has been pooled from many human donors. In the fall of 2008 CIDP became an approved indication for IVIg in both Canada and the United States. OBJECTIVES: To evaluate the clinical effectiveness and safety of IVIg for the treatment of CIDP through a systematic review of the literature. METHODS: The Medline (1950-2009; In-Process & Other Non-Indexed Citations) and EMBASE (1980-2009) databases were searched through the Ovid interface. A methodological filter was applied to limit retrieval to clinical trials, MAs, or SRs. Retrieval was limited to humans and no language restrictions were employed. Extracted data were pooled to estimate the effect size of IVIg treatment based on the random-effects model.   RESULTS: Nine unique RCTs were identified. Three of the nine trials compared IVIg therapy to an active comparator (plasma exchange (PE), PE using extracorporeal immunoadsorption, or oral prednisolone), and the other six trials were placebo-controlled. There was no incremental benefit seen in the primary outcomes when comparing IVIg therapy and the active comparator. Five of the six placebo-controlled trials showed IVIg therapy to be superior to placebo based upon a variety of disability or impairment outcomes. CONCLUSIONS: IVIg therapy is statistically superior to placebo treatment in reducing the disability and impairment for CIDP patients. IVIg demonstrates similar effectiveness as the alternative treatment strategies of PE and methyprednisolone.