Background: Zinc is an essential trace nutrient, has important function to play in growth. Many studies have indicated that a negative Zinc balance exist in preterm and small for gestational age infants until approximately 37 weeks of gestation. Several workers have recorded an improved Zinc status, good weightgain and better linear growth velocities in preterm infants supplement with Zinc. Aim of study: The current study evaluates the effect of zinc supplementation on growth parameters of premature infants. Also to determine the role of zinc therapy in treatment of acute diarrhea in children aged 3 months - 2 years. Methods: This randomized clinical trial study was done in Imamein Kadhemain Medical City, pediatric department, in the period from 1st December 2013 to 30th july2014. One hundred hospital born preterm infant with gestational age <37 weeks, whose were admitted to the hospital , when they were ready for discharge ,they randomly assigned to receive Zinc & multivitamins (50 neonates) ormultivitamins only (50 neonates). Multivitamin are vitamin A, vitamin D, iron & folic acid. The Zinc group received it in a dose of2 mg/kg/day. Weight, length and head circumference were followed up after 4 weeks. Results: In this study no significant difference in weight, length and head circumference between the zinc group & control group at the start but a significant difference were found at 4 weeksfollow up (P<0.05). Conclusion: Zinc supplementation for preterm babies was found effective to enhance the growth in early weeks of life, while in regard to difference in growth according to types of feeding there is no significant difference.