Uterine artery pseudoaneurysm is a rare cause of secondary postpartum hemorrhage. Herein, we report a case of uterine artery pseudoaneurysm, with postpartum hemorrhage commencing 22 days after uncomplicated vaginal delivery. Intermittent bleeding occurred during conservative observation. Transvaginal ultrasound color Doppler imaging revealed swollen vascular structures that suggested arteriovenous malformations, and a saccular dilatation of blood vessels. However, it was insufficient to definitively diagnose the condition as pseudoaneurysm. Meanwhile, the three-dimensional computed tomography angiogram was effective in demonstrating a pseudoaneurysm in the uterus, and an absent early venous return sign, leading to the final diagnosis of a pseudoaneurysm. The patient was successfully treated with transarterial embolization using gelatin sponge pledgets. No bleeding or recurrence of the pseudoaneurysm was observed 2 months after embolization.