ABSTRACT: Infantile hypertrophic pyloric stenosis is a concerning cause of nonbilious vomiting in the neonatal population. Although a number of etiological theories exist, its exact cause remains nebulous. The question of an infectious etiology (or contribution) has been previously examined in case reports and case series, with recent support through suggestions of seasonality and familial aggregation with unclear inheritance patterns. The present review discusses the published literature regarding infectious etiologies of infantile hypertrophic pyloric stenosis. Furthermore, it attempts to demonstrate that newer research regarding an NOS1 genetic etiology does not exclude, but rather can be consistent with, an infectious etiology.