Probiotics are live microorganisms that produce a benefit to the host when provided in adequate amounts from food or supplements. There is an increased interest in the use of probiotics in the management and treatment of complex medical conditions. Recommendations for probiotic supplementation in the pediatric population are often conflicting due to limited research in many pediatric disease states. Research on single and multistrain probiotics has shown promise for some pediatric populations. This review discusses the research available for probiotic supplementation for children with irritable bowel syndrome, Crohn's disease, diarrhea, short bowel syndrome, human immunodeficiency virus, and food allergies. Probiotic safety also is discussed.