Abstract Aims Although the delivery catheter system for pacemaker-lead implantation is a new alternative to the stylet system, no randomized controlled trial has addressed the difference in right ventricular (RV) lead placement accuracy to the septum between the stylet and the delivery catheter systems. This multicentre prospective randomized controlled trial aimed to prove the efficacy of the delivery catheter system for accurate delivery of RV lead to the septum. Methods and results In this trial, 70 patients (mean age 78 ± 11 years; 30 men) with pacemaker indications of atrioventricular block were randomized to the delivery catheter or the stylet groups. Right ventricular lead tip positions were assessed using cardiac computed tomography within 4 weeks of pacemaker implantation. Lead tip positions were classified into RV septum, anterior/posterior edge of the RV septal wall, and RV free wall. The primary endpoint was the success rate of RV lead tip placement to the RV septum. Results Right ventricular leads were implanted as per allocation in all patients. The delivery catheter group had higher success rate of RV lead deployment to the septum (78 vs. 50%; P = 0.024) and narrower paced QRS width (130 ± 19 vs. 142 ± 15 ms P = 0.004) than those in the stylet group. However, there was no significant difference in procedure time 91 (IQR 68–119) vs. 85 (59–118) min; P = 0.488 or the incidence of RV lead dislodgment (0 vs. 3%; P = 0.486). Conclusion The delivery catheter system can achieve a higher success rate of RV lead placement to the RV septum and narrower paced QRS width than the stylet system. Trial registration number jRCTs042200014 (https://jrct.niph.go.jp/en-latest-detail/jRCTs042200014) Graphical Abstract Graphical Abstract Outcome comparison between delivery catheter and stylet systems. The delivery catheter system can achieve a higher RV lead placement on the RV septum success rate and a narrower paced QRS width than the stylet system. RV, right ventricular.