Neonatal lupus erythematosus (LE) is a rare disease associated with the transplacental passage of maternal autoantibodies to infants who manifest congenital heart block, skin disease, and less commonly, hematologic and hepatic disease. Pulmonary disease is a rare manifestation of neonatal LE and has presented as transient pneumonitis. In this report we describe an infant with neonatal LE who had the classic skin and hematologic findings of the disease in addition to pulmonary disease which might be attributed to neonatal LE-related pneumonitis, but in fact was caused by a concomitant Pneumocystis carinii infection. This case demonstrates the importance of looking for other causes of pulmonary disease in neonatal LE patients.