A sudden unexpected death is reported in a 15-month old boy, born with an extremely low birth weight and then had suffered prolonged respiratory complications arising from infantile respiratory distress syndrome. The autopsy revealed severe bronchopulmonary dysplasia (BPD) in his lungs with secondary pulmonary heart disease; a tracheotomy was carried out to enable his survival. The cause of death was established as being acute cardiac and pulmonary failure due to severe BPD, rather than mechanical asphyxia. The perilaryngeal lymph nodes were also significantly enlarged and closely surrounded the vagus bilaterally. Such cervical lymphadenopathy could have resulted in the mechanical compression of the vagus upon movement of the neck. For this reason, anatomical examination of the cervical portion of the vagus and its path may be of great significance when analyzing the cause of death in the cases of sudden infant death.