Objective: Although pediatric central venous catheterization is performed using ultrasound guidance, it is still a challenge. This study aimed to investigate the efficacy of the syringe-free, long-axis in-plane approach and compared the short-axis classic out-of-plane approach for ultrasound-guided central venous catheter placement in critically ill pediatric patients. Design: Prospective randomized study. Setting: Single institution, tertiary university hospital, pediatric care unit. Participants: The study comprised 60 patients ages three months to 15 years. Interventions: Participants were randomly divided into two equal groups. Group I (n = 30) incorporated patients who underwent the long-axis, syringe-free in-plane approach, and group II (n = 30) incorporated patients who underwent the short-axis out-of-plane approach. Measurements and Main Results: Performing time, number of needle passes, number of skin punctures, first-pass success rate, and related complications were evaluated. There were no differences between the two groups in terms of demographics and vein-related measurements (p > 0.05). Performing time was statistically shorter in group I compared with group II (32 [25-38] v 58 [42-70] s; p < 0.001). There was no statistical difference between first-pass success rates between groups (group I 86.6% v group II 80%; p = 0.731). There were no significant differences between the groups in the number of needle passes and skin punctures (p = 0.219 and 0.508, respectively). Complications occurred in both groups, but there was no significant difference (4/30 v 7/30; p = 0.317). Conclusions: The syringe-free, long-axis in-plane approach can be a safe and fast alternative for pediatric catheterization.