Introduction: Pulmonary involvement is relatively frequent in adult and juvenile patients with Systemic Lupus Erythematosus (SLE), but its occurrence in newborns with Neonatal Lupus Erythematosus (NLE) is exceedingly rare. Case report: A mother with SLE and positive anti-SSA/Ro and anti-SSB/La delivered a preterm newborn with third-degree heart block and positive anti-SSA/Ro confirmed postnatally. A temporary pacemaker was placed at D3 and a definitive pacemaker only at D15 due to sepsis with concurrent mild respiratory failure. Despite adequate antibiotic therapy, negative cultures and decreasing inflammatory parameters, at D17 severe respiratory failure ensued, requiring mechanical ventilation. Chest x-ray showed symmetrical interstitial infiltrates. Acute Lupus Pneumonitis (ALP) and Pulmonary Embolism were suspected and the chest angio-CT revealed diffuse ground glass opacities. After 3 methylprednisolone pulses he improved rapidly. Discussion: The diagnosis of ALP in NLE, mostly one of exclusion, is a challenge. A high degree of suspicion and a multidisciplinary approach to these patients are fundamental in order not to delay establishing a diagnosis. Although few reports in the literature, early aggressive treatments are probably crucial for a favorable outcome without long-term sequelae.