The patients with organic acidemia involving propionate metabolism might have tendenceny to ARDS due to the possible role of toxic metabolites in the ARDS pathogenesis. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition due to hyperinflammation caused by aberrant proliferation of activated lymphocytes and macrophages secreting high levels of cytokines. Hemophagocytic lymphohistiocytosis (HLH) may develop secondary to infections, malignancies, immune deficiency syndromes, rheumatologic and metabolic disorders. Associations between hemophagocytosis and inborn errors of metabolism including lysinuric protein intolerance, multiple sulfatase deficieny, galactosemia, Gaucher Disease, Pearson Syndrome, galactosialidosis have previously been reported in the literature. We report three cases with disorders of propionate metabolism one with methylmalonic acidemia and two with propionic acidemia developing secondary hemophagocytosis during the course of their metabolic disease. This is the first report of such an association.