A modified protocol of uterine fibroid embolization (UFE) is proposed for alleviating the postinterventional pain. This randomized and double-blinded clinical trial is to evaluate the effectiveness of intra-arterial infusion of dilute lidocaine for postinterventional pain relief in UFE. Forty-six patients who underwent UFE were randomly grouped equally. In the test group, after the poly(vinyl alcohol) embolization was complete, a dilute lidocaine solution with 40 mg in 6.0 ml, 3.0 ml for each side or 4.0 and 2.0 ml for two sides, was given through the catheter. In the control group, the patients received 6.0 ml of saline solution as a placebo. A simple pain degree classification method for patient self-evaluation was developed. A questionnaire was completed by each patient to record the degree of pain during five periods; these were during the procedure, the first 12 h, the second 12 h, between 24 and 48 h, and between 48 and 72 h. The numbers of patients with the same degree of pain in the five time segments from the two groups were statistically compared. Compared with the control group, the patients in the test group experienced less pain within 48 h after the procedure (p<0.01). The results suggest that this improved UFE protocol is a simple approach to prevent the acute postinterventional pain of UFE.