A 5-day-old girl presented with thrombocytopenia, leukopenia, anemia and crusted purpura on the skin. The diagnosis Langerhans' cell histiocytosis (LCH) was suspected on clinical grounds and subsequently confirmed by histopathological examination of a skin biopsy. Cytological examination of a bone marrow aspirate revealed numerous histiocytes, which is suspect for bone-marrow infiltration by LCH. LCH is a condition in which a clonal population of Langerhans' cells accumulates in various tissues, causing tissue damage and/or dysfunction. The prognosis of this disease depends on the age of the patient, the extent of the disease and the presence of vital organ failure. In case of organ dysfunction, systemic chemotherapy is indicated. Although very rare, LCH can be a life-threatening disease. Early diagnosis can improve chances of survival. We briefly discuss diagnostic procedures and treatment.