Background: Minimal Enteral Nutrition (MEN) is reported to improve gastrointestinal disaccharides activity, hormone release, motility, and microbial flora. Clinical benefits include improved milk tolerance, greater postnatal growth, reduced systemic sepsis and shorter hospital stay. Very little is known about its effect on Superior Mesenteric Artery (SMA) blood flow velocity in premature infants. Aim: the aim of this study is to detect changes in superior mesenteric artery blood flow occurring in preterm infant after MEN. Patient and Method: It is a pretest-posttest prospective cohort study. SMA blood flow parameters were measured with Doppler Ultrasonography on SMA for analysis of Doppler flow velocity waveforms, that includes end-diastolic velocity, peak-systolic velocity, time-averaged mean velocity, resistive index and pulsatility index on 40 stable preterm neonates (gestational age range 28-33 weeks, weight at examination range 1000-2800 g, postnatal age range 1-4 days). They were admitted to the neonatal intensive care unit of Al-ZahraUniversityHospital during the period from July 2016 to December 2017. Measurements were performed before and after minimal enteral feeding. The baseline SMA blood flow was measured before test feed (10 to 15 ml/kg/day) and repeated 30 minutes after the feed. Results: Comparing SMA velocities and indices before and after minimal enteral nutrition indicated a significant increase in peak systolic velocity (PSV), end diastolic velocity (EDV) and time- average mean velocity (TAMV), and a significant decrease in pulsatility index (PI) and resistance index (RI) after 30 min from MEN. the mean flow velocities of the (SGA) group were significantly higher than (AGA) group. the mean flow velocities of the early fed group were significantly higher than late fed group No correlation has been found between SMA parameters and studied vital signs or SpO2. Conclusion: MEN improves SMA blood flow especially in small for gestational age, thus it might influence the structure and promote development of the premature infant's gastrointestinal tract. Recommendation:  use of early minimal enteral nutrition especially in very premature baby and should be used as an adjunct to parenteral nutrition.