Background: Peripheral venipuncture in infants and children is technically challenging because their veins are small and located deep in the subcutaneous tissue which makes them difficult to palpate or visualize. In this study, we sought to determine if the use of the VeinViewer (Luminetx Corporation, Memphis, Tenn) in children facilitates peripheral venous access. Materials and Methods: This was a nonblinded, randomized controlled trial of a convenience sample of pediatric patients younger than 20 years old requiring intravenous access in the pediatric ward. Prior to the randomization, the DIVA (difficult intravenous access) score of 4-variable proportionally weighted rule (3 points for prematurity, 3 for younger than 1 year, 1 for 1–2 years of age, 2 for vein not palpable, and 2 for vein not visible) was estimated. We also decided vein categories (easy, intermediate and difficult) according to nurse opinion. Then patients were randomly allocated to undergo VeinViewer-assisted or standard peripheral venous access. Primary end point was the first-attempt success rate. Stepwise logistic regression analysis was used to identify factors associated with the first-attempt success. Results: A total of 111 patients were evaluated: 54 in the VeinViewer group and 57 in the traditional group. Patient demographics and factors related to the success of vein access were similar in both groups. Analysis by vein assessment category yielded a similar rate of successful first-attempt in both groups for easy veins. However, for difficult veins over DIVA score 4, first-attempt success rate increased from 25% in the traditional group to 58.3% in the VeinViewer group (p=0.026). Factors associated with the first-attempt success were patient age and type of delivery. Patient body mass index and the experience of nurse had no significant impact on the first-attempt success. Conclusion: The VeinViewer facilitates the peripheral venous access in pediatric patients with difficult veins enhancing the first-attempt success rate.