Acute post-mastectomy pain can cause adverse impacts on the patients as delayed discharge from post-operative recovery area, impairs pulmonary and immune functions, increases risk of ileus, thromboembolism, myocardial infarction and may lead to increased length of hospital stay. It is also an important factor leading to the development of chronic post mastectomy pain syndrome (PMPS) in almost half of the patients. Various regional anesthetic techniques have been described for postoperative pain relief after mastectomy, for example, thoracic epidural anesthesia, intercostal nerve block, paravertebral block, serratus anterior plane block, and pectoral nerve I and II blocks. All of them offer satisfactory pain relief after mastectomy. Erector spinae plane block is a novel para-spinal regional anesthesia technique, , promises to provide effective visceral as well as somatic analgesia after carcinoma of the breast surgeries. The ultrasound-guided rhomboid intercostal block sub-serratus plane block (RISS) is a novel analgesic technique The RISS block anesthetizes the lateral cutaneous branches of the thoracic intercostal nerves and can be used in multiple clinical settings for chest wall and upper abdominal analgesia