Haemophagocytic lymphohistiocytosis (HLH) is a rare and rapidly progressive disease which, untreated, invariably leads to death. Gaucher disease is a rare lysosomal storage disorder. The acute neuronopathic variant; type II, is also rapidly progressive. We report an infant with Gaucher disease type II manifesting as HLH. Immunoblot revealed a deficiency of Munc 13-4, an intracellular protein responsible for docking of secretory lysosomes. This, and other possible pathogenetic mechanisms to explain the link are discussed.