We report a case of haemophagocytic lymphohistiocytosis associated with acute myeloid leukaemia. The usual etiologies of haemophagocytic lymphohistiocytosis, including viral infections, were negative. Haemophagocytic lymphohistiocytosis secondary to acute myeloid leukaemia is often underestimated and undiagnosed. Haemophagocytic lymphohistiocytosis may be masked by the tumour process, often making the diagnosis difficult.