In spite of the availability and widespread use of vaccines, pertussis is far from controlled. Newborns and infants too young to be fully vaccinated, born from mothers with low antibody titers to Bordetella pertussis, are highly susceptible to infection and at risk of severe disease and death. Pertussis associated with pulmonary hypertension in the newborn is often fatal. The authors report a clinical case of severe pertussis -induced respiratory failure associated to severe pulmonary hypertension in a neonate successfully treated with sildenafil and inhaled nitric oxide.