At birth, the neonate is an obligate nasal breather and any compromise of the nasal passages is potentially life threatening. It is important for the otorhinolaryngologist to quickly recognize and manage even subtle constrictions or obstructions of the nasal passages in this age group. Many times the nasal airway is disregarded as the source of airway difficulty if small catheters can be passed. Conversely, the inability to pass nasal catheters is often arbitrarily diagnosed as choanal atresia or stenosis. This limited outlook can delay appropriate therapy. The differential diagnosis of nasal obstruction in the neonate is presented wit emphasis on evaluation of nasal obstruction in anatomically normal appearing noses.