Surgery is the primary therapeutic intervention for breast cancer and can result in significant postoperative pain. We searched the current literature and performed a meta-analysis in order to compare the analgesic efficacy of the pectoral type-2 (Pecs II) block with systemic analgesia alone and with a thoracic paravertebral block for breast cancer surgery. Primary outcome was postoperative opioid consumption in the first 24 h after surgery. ⋯ The Pecs II block significantly reduced postoperative opioid consumption (standardised difference in means: -13.64 mg oral morphine equivalents; 95%CI: -21.22 to -6.05; p < 0.01) and acute postoperative pain at all intervals in the first 24 h after surgery compared with systemic analgesia alone. Compared with the thoracic paravertebral block, the Pecs II block resulted in similar postoperative opioid consumption (standardised difference in means: -8.73 mg oral morphine equivalents; 95%CI: -18.16 to 0.69; p = 0.07) and postoperative pain scores after first measurement. In conclusion, the Pecs II block offers improved analgesic efficacy compared with systemic analgesia alone and comparable analgesic efficacy to a thoracic paravertebral block for breast cancer surgery.