Since infant botulism was first identified three decades ago, our understanding of botulinum toxins and the organisms that produce them has grown. A newer classification system now recognizes Clostridium baratii and Clostridium butyricum along with Clostridium botulinum as causative agents. Recently, increasing therapeutic use of botulinum toxins has sparked substantial new research into their mechanisms of action. This research, and some case reports from infants sickened by unusual botulinum toxins suggest that disease caused by different toxin types may result in varying clinical presentations. Perhaps most significantly for pediatricians and child neurologists, a specific treatment for infant botulism has just been approved. This article reviews the clinical presentation, diagnosis, and treatment of infant botulism, including human botulism immune globulin, and discusses the various organisms and toxins that cause this disease.