Objective: To investigate the clinical efficacy of preemptive analgesia with combination use of parecoxib sodium and dezocine in radical mastectomy. Methods: One-hundred and seventy patients undergoing radical mastectomy were divided into control group, preemptive analgesia group and combined preemptive analgesia group, and were injected with normal saline, parecoxib sodium or parecoxib sodium plus dezocine before anesthesia induction, respectively. The visual analog scale (VAS) scores of the patients were recorded at postoperative 2, 6, 12, 24, and 48 h for comparing the analgesic effects among the groups, and the cardiovascular responses and incidence of adverse reactions were also compared among groups. Results: The VAS score in preemptive analgesia group or combined preemptive analgesia group was significantly lower than that in control group at any predefined time point (all P<0.05), which in combined preemptive analgesia group was significantly lower than that in preemptive analgesia group at postoperative 2 h (P<0.05), and still lower than that in preemptive analgesia group at postoperative 6 to 48 h, but did not reach statistical significance (all P>0.05). The heart rate (HR) and mean arterial pressure (MAP) of patients in both preemptive analgesia group and combined preemptive analgesia group were lower than those in control group before the induction of anesthesia to completion of operation, and were significantly lower than those in control group from 5 min after endotracheal intubation to completion of operation (all P<0.05), while no significant difference was observed between the two preemptive analgesia groups (all P>0.05). The incidence of adverse reactions in either preemptive analgesia group or combined preemptive analgesia group was significantly lower than that in control group (both P<0.05), and incidence of nausea, vomiting and dizziness in combined preemptive analgesia group was higher than that in preemptive analgesia group, but no statistical significance was reached (P>0.05). Conclusion: Preemptive analgesia of parecoxib sodium plus dezocine has good clinical efficacy in radical mastectomy, which may not cause the increase of cardiovascular response, but probably increase the incidence of nausea, vomiting and dizziness.