Objective: To compare effects of pectoral nerves II (Pecs II) block and thoracic paravertebral nerve (TPVN) block on perioperative analgesia, inflammatory cytokines and quality of early postoperative recovery after modified radical mastectomy. Methods: A total of 80 patients scheduled for modified radical mastectomy in our hospital from March 2019 to March 2021 were randomly divided into a Pecs II group and a TPVN group, 40 cases in each group, meanwhile, 20 healthy people in the same period served as the control group. Pecs II block was used in the Pecs II group and TPVN block was used in the TPVN group. The Visual Analogue Scale (VAS) at 0.5, 2, 4, 6, 12, 24, 48 h after the operation, and duration of analgesia, sufentanil dosage within 24 h after the operation were compared between the 2 groups. The serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected before operation, 1 and 3 d after the operation, and the scores of 40-item Quality of Recovery Questionnaire (QoR-40) were compared at 1, 2 and 3 d after the operation and the adverse reactions were observed. Results: Compared with the TPVN group, the VAS score of the Pecs II group was significantly lower at 2–24 hours after the operation, the duration of analgesia was longer, and sufentanil dosage was less in 24 h after the operation (P<0.05). The levels of IL-6 and TNF-α of the Pecs II group at 1 and 3 d after the operation were significantly lower than those of the TPVN group (P<0.05). The QoR-40 score at 1–3 d in Pecs II group was significantly higher than that in the TPVN group (P<0.05). There was no significant difference in the total incidence of adverse reactions between the 2 groups (17.50% vs 25.00%, P>0.05). Conclusion: Compared with TPVN block, Pecs II block has better postoperative analgesia effect in patients with modified radical mastectomy, and can effectively reduce the level of inflammatory factors and improve the quality of early postoperative recovery.