AbstractBackground: Traditionally, orogastric tube (OGt) insertion length is determined by nose-earlobe-xyphoid (NEX) measurement. Minimum insertion lengths have been proposed for prematures but not for extremely low birth weight (ELBW) infants. Objective: To determine minimum OGt insertion length for intragastric placement in ELBW infants using NEX measurements alone and NEX measurements in conjunction with a novel regression formula. Design/Methods: Retrospective phase (83 pts): Correct intragastric placements were identified and a regression formula for predicting insertion length was created. Prospective phase (50 pts): Nurses were instructed to use NEX measurements if they coincided within 1 cm with estimates from the regression formula (birth weight g × 0.004 + 9.44 = cm insertion length). In cases of discrepancy, measurements calculated by the formula were used. Results: Using NEX method alone, the first OGt placements were in the esophagus (6%) straight in the stomach (6%), reversed in the stomach (4%), in the duodenum (1%) and “correctly” placed diagonal in the stomach (83%). Using NEX measurement and the regression formula, OGt placements were diagonal in the stomach (96%), or straight in the stomach (4%), with none in the esophagus, reversed in the stomach or in the duodenum. The difference in correct placements by the two methods was significant. Conclusions: NEX measurements in conjunction with a minimum insertion length estimated from a formula should decrease the number of malpositioned OGt in ELBW infants.