Aims & Objectives: Compare the effectiveness of transillumination by infrared(NIR) with light emitting diodes(LED) in the success of first attempt in children at risk for difficult puncture. Methods:. Methods: Clinical trial conducted in Pediatric Emergency Unit, in 2019, in São Paulo-Brazil, with children who had risk factors for failure of puncture, were hemodynamically stable and which are punctured with LED or NIR device. Data collection was performed by evaluation of the patient, according to the decision-making flowchart for selection of children classified as a difficult catheterization, health interview and observation of the procedure. Randomization was performed to verify which equipment would be used, GLED- LED or GNIR - NIR device. The outcomes studies were successful on the first attempt, reason of failure and the ease of transillumination procedure. The association of clinical variables was carried out to verify the risk factors for failure. Results: GLED was composed by 67 children, with 63.8% of success of first attempt, and GNIR, by 58 patients, with 59.7% of success of first attempt. In both groups the reason of failure was hematoma and more than 91.0% of professionals, used to like to perform the venous puncture using the transillumination. Children who had dark skin, chronic disease, difficult-to-see veins(p=0,03), history of multiple punctures, complications associated with intravenous therapy as risk factors for difficult puncture, had a higher success in the first attempt with both equipment. Conclusions: Success of first puncture was similar with both technologies. However children with risk factors for difficult puncture have benefited from the use of technology.