A toddler undergoing treatment for refractory Langerhans cell histiocytosis (LCH) developed concurrent hemophagocytic lymphohistiocytosis (HLH). These are thought to be distinct histiocytic disorders, with different pathophysiologies, diagnostic criteria, and treatments. HLH in a patient with LCH is thought to be quite rare. In this report, we review the presentation of our patient, as well as review the existing literature of other pediatric patients who have been diagnosed with both LCH and HLH.