As most prior reviews on NA focus on adult transplant patients, there is a need for a comprehensive overview on adherence to the immunosuppressive regimen in pediatric kidney transplant patients. This systematic review searched for English-language papers (1990-2008) addressing the prevalence of NA to the immunosuppressive regimen, its consequences, determinants, and interventions in pediatric kidney transplant patients (< age 21 yr). We found 36 papers, showing a prevalence of NA (weighted mean) of 31.8% with adolescents being more at risk compared to younger patients. About 44% of all graft losses and 23% of late acute rejection episodes are associated with NA. Most studies investigated socio-economic, condition-related or treatment-related determinants. Only one educational intervention has been tested but yielded inconclusive results. NA to the immunosuppressive regimen is prevalent with serious clinical consequences in pediatric kidney transplant patients, but the economic consequences have not yet been explored. More studies on determinants of NA are needed. The literature currently lacks fully powered RCTs testing adherence-enhancing interventions. The results of this systematic review identify the gaps in the present evidence-based information regarding NA and can be used as a tool to pursue future adherence research in pediatric populations.