The development of lipid aspiration pneumonia after chronic nasopharyngeal installation of mineral oil was first described in 1925 by Laughlin. Since that time this entity has been well recognized and numerous substances have been identified or implicated as the aspirated material. The classic radiographic appearance of severe chronic lipid aspiration pneumonia has been described as consisting of intense perihilar infiltrates. However, the radiographic findings are more often non-specific and usually consist of varying degrees of diffuse interstitial infiltrates that tend to be more prominent in the perihilar regions and the right lung. We are reporting a case of biopsy-proven lipid aspiration pneumonia in an infant with known gastro-esophageal reflux (GER) who had medium-chain triglyceride oil administered via nasogastric tube. Serial roentgenograms demonstrated a changing pulmonary pattern from diffuse bilateral interstitial infiltrates initially to a diffuse alveolar pattern at the time of the lung biopsy. Modern medicine has developed new methods for providing nourishment to sick newborns and infants to improve their nutritional status and help them to grow. One such method involves the administration of medium-chain triglycerides (MCT oil) into the GI tract via a nasogastric or nasoenteral tube. The purpose of this report is to describe a significant complication of this method of providing nutrition to an infant with gastroesophageal reflux (GER) and the diagnostic dilemma it presented.