Radial artery occlusion (RAO) occurs in 2% to 18% of patients after transradial access (TRA) cardiac catheterization. Using a kaolin-filled pad (QuikClot) reduces compression time during TRA and might reduce RAO. We examined the RAO risk with the kaolin-filled pad after TRA cardiac catheterization.This was a prospective cross-sectional study of 260 patients who underwent TRA cardiac catheterization in a cardiac ward of a Medical Center from 2012 to 2016. Patients were randomly assigned to 1 of 2 groups: the case group (n = 130) was postoperatively treated with a kaolin-filled pad, and the control group (n = 130) was treated with conventional hemostasis. Color duplex ultrasound was used to evaluate the 24-hour and 1-month postoperative radial artery flow velocity, diameter, patency, and RAO risk.RAO risk was not significantly different between the case and control groups after 24 hours (4.6% vs 5.4%, P = .776) or after 1 month (5.4% vs 6.1%, P = .789), regardless of whether it was a first TRA cardiac catheterization (after 24 hours [P = .153] or after 1month [P = .617], respectively) or a repeated TRA cardiac catheterization (after 24 hours [P = .754] or after 1month [P = .753], respectively).Using a kaolin-filled pad after TRA cardiac catheterization did not significantly reduce RAO risk compared with conventional hemostasis.