Marine envenomations can cause a diverse array of clinical syndromes. Systemic and life-threatening reactions, as well as delayed presentations, can occur. The pediatric population is at higher risk for serious reactions to envenomations because their greater body surface area and smaller body mass can lead to a higher relative venom load. Although the majority of the literature on marine envenomations is of low quality, the available literature does suggest that management varies depending on the geographic location. This issue reviews both common and life-threatening presentations of marine envenomations, highlights key aspects of the history and physical examination that will help narrow the differential, and offers recommendations for management based on the envenomating creature and geographic location.