The purpose of this article was to present the case of a premature infant who displayed immature feeding progression because of nasal occlusion. Two male preterm infants of 33 weeks' gestational age at birth from a larger randomized trial were observed in a comparative case study. Using a prospective design, feeding assessments were conducted weekly from initiation of oral feeding until hospital discharge. Sucking organization was measured using the Medoff-Cooper Nutritive Sucking Apparatus (M-CNSA), which measured negative sucking pressure generated during oral feedings. Oral and nasogastric (NG) intake and vital signs were recorded. At 35 weeks, infant A demonstrated an immature feeding pattern with the M-CNSA NG feedings prevailing over oral feedings. When attempting to feed orally, infant A exhibited labored breathing and an erratic sucking pattern. During the third weekly feeding evaluation, nasal occlusion was discovered, the NG tube was discontinued, and phenylephrine (Neo-Synephrine) and humidified air were administered. Following treatment, infant A's sucking pattern normalized and the infant maintained complete oral feeding. Infant B demonstrated normal feeding progression. Nasal occlusion prevented infant A from achieving successful oral feeding. The M-CNSA has the ability to help clinicians detect inconsistencies in the sucking patterns of infants and objectively measures patterns of nutritive sucking. The M-CNSA has the potential to influence clinical decision making and identify the need for intervention.