We studied the cytokine profile of two siblings with neonatal lupus erythematosus (NLE) born to a mother positive for serum anti-Ro and -La antibodies, who did not receive any medication during the two pregnancies. The first sibling was found to have complete atrioventricular block in utero and became severely ill after birth. He fulfilled the diagnostic criteria for hemophagocytic lymphohistiocytosis on day 2. The second sibling did not have any fetal symptoms. He was generally stable after birth, but with typical skin rash. Laboratory data suggested that they both had hypercytokinemia during the neonatal period, requiring corticosteroid treatment. Interleukin (IL)-6, interferon-γ, IL-8 and monocyte chemotactic protein-1 were elevated in both cases, while IL-12, IL-13 and IL-17 were elevated only in the second sibling. Comparison of the cytokine profiles suggests the potential roles of different cytokines in the onset and clinical manifestations of NLE.