The aim of this review was to identify whether non-professional volunteer support might be effective in improving the uptake of child immunization. The Cochrane Library, Medline, Cumulative Index to Nursing and Allied Health Literature and Embase databases were searched for randomized controlled trials comparing groups of parents supported by lay volunteers with those supported by conventional child health services. Two such trials met the review criteria. These studies suggested that using non-professional volunteers to support parents can be an effective strategy for improving the uptake of immunization in children younger than 2 years, but there is limited evidence to suggest that this effect is sustained for older children, Equally, intervention effects could, because of differing cultural and sociodemographical factors, be less marked when applied to British populations, in which the parents of pre-school-aged children have access to immunization support from a generic health visiting service.