The efficacy of the short-axis out-of-plane (SA-OOP) approach with and without dynamic needle tip positioning (DNTP) remains unclear. This systematic review with network meta-analysis aimed to compare the success rate of arterial line insertion in children using the SA-OOP approach with and without DNTP and the palpation technique. We searched MEDLINE (via PubMed) and the Cochrane Central Register of Controlled Trials. We included randomized controlled trials that compared two of the following techniques for arterial line insertion in children: (1) the ultrasound-guided SA-OOP approach with DNTP; (2) the ultrasound-guided SA-OOP approach without DNTP; and (3) the palpation technique. A network meta-analysis was performed. The outcomes were first-attempt and overall success rates. Eight studies were finally included in this network meta-analysis. The ultrasound-guided SA-OOP approach with DNTP was associated with increased first-attempt (relative risk RR = 3.45 [95% confidence interval (CI) 2.51–4.74]) and overall success rates (RR = 1.81 [1.41–2.32]) when compared with palpation. The same approach performed without DNTP was also associated with increased first-attempt (RR = 1.96 [1.59–2.42]) and overall success rates (RR = 1.25 [1.05–1.49]) when compared with palpation. The ultrasound-guided SA-OOP approach with DNTP was associated with increased first-attempt (RR = 1.76 [1.26–2.44]) and overall success rates (RR = 1.45 [1.10–1.91]) when compared with the same approach performed without DNTP. DNTP should be performed during the ultrasound-guided SA-OOP approach for arterial line insertion in children, as this can help increase first attempt and overall success rates.