There were 146 patients with a median age of 4.6 years (range, 0.18-17.1 years), 46.6% were male, 80.8% were light skin colored, and 15.7% were younger than 2 years. The first-attempt success rates were 75% (95% CI, 63.8-84.2%) using AV300 and 73% (95% CI, 61.9-81.9%) using the standard method (P = 0.85). Patients with dark or medium skin color were 0.38 times less likely to have a successful first attempt than patients with light skin color. The difference between the two treatment groups in number of skin punctures and the time to insertion was not significant. Although the AV300 was easy to use and improved visualization of the veins, we found no evidence that it was superior to the standard method of intravenous cannulation in unselected pediatric patients under anesthesia.