Objective: Dehydration is a significant threat to the health of children worldwide and a major cause of death in resource-scarce settings. Although multiple studies have revealed that oral and intravenous (IV) methods for rehydration in nonsevere dehydration are nearly equally effective, little is known about effectiveness beyond these 2 techniques. With this systematic review we analyzed the effectiveness of nonoral and nonintravenous methods of rehydration., Methods: The Medline, Cochrane, Global Health, Embase, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched for articles on intraosseous (IO), nasogastric (NG), intraperitoneal (IP), subcutaneous (hypodermoclysis), and rectal (proctoclysis) rehydration through December 2009. Only human pediatric studies that included data on the effectiveness or complications of these methods were included., Results: The search identified 38 articles that met the inclusion criteria: 12 articles on NG, 16 on IO, 7 on IP, 3 on subcutaneous, and none on rectal rehydration. NG rehydration was as effective as IV rehydration for moderate-to-severe dehydration. IO rehydration was effective and easy to obtain, although only 1 randomized trial was identified. IP rehydration had some benefit for moderate dehydration, although none of the trials had control groups. Limited data were available on subcutaneous rehydration, and only 1 case series showed benefit., Conclusions: NG rehydration should be considered second-line therapy, after oral rehydration, particularly in resource-limited environments. IO rehydration seems to be an effective alternative when IV access is not readily obtainable. Additional evidence is needed before IP and subcutaneous rehydration can be endorsed.