Post-thoracotomy pain is one of the most severe forms of post-operative pain that can be attributed to muscle incision, rib retraction or resection, and damage to the intercostal nerves. Inadequate control of this post-operative pain can contribute to a deterioration of the respiratory function, with limitation of the ventilation, appearance of atelectasis, ineffective cough, and increased risk of infectious complications. Moreover, recent evidence shows that persistent pain after surgery, in addition to being responsible for chronic post-surgical pain syndrome, is associated with a delay in post-operative recovery and a return to normal daily life activities. The most common techniques for the management of post-thoracotomy pain are in addition to systemic intravenous analgesia, thoracic epidural, paravertebral nerve block and intercostal nerve block. Although the thoracic epidural has been considered for years the gold standard for the control of post-operative pain following thoracotomy, it is not risk-free, requires an expert operator, and can be contraindicated in some categories of patients. The intercostal nerve block, performed through the injection of the local anesthetic in multiple intercostal spaces before performing thoracotomy, may be one of the alternatives to a thoracic epidural in terms of safety and efficacy and is technically easy and quick to perform. This block is found to be particularly effective in reducing post-operative pain when associated with a mini-thoracotomy, helping to improve the outcome of patients undergoing major lung resection. A technique of more recent description (2016) is the erector spinae plane block (ESP) . This interfascial block is performed in the posterior thoracic region homolaterally at the site of the intervention at the level of the T5 transverse process (fifth thoracic vertebra), the ultrasound marker of the block. The ESP block is easy and safe to perform thanks to the ultrasound-guided method and the absence of vascular-nerve structures at risk of damage in the vicinity of the injection site and allows analgesia of the posterior and anterolateral thoracic wall and of the axillary region. In fact, cadaveric studies have shown an anesthetic distribution both in the cranial caudal sense (T2-T8) along the fascia between erector spinae and large rhomboid, and in the anteroposterior direction, with the blockage of the spinal thoracic nerve roots. ESP block was described in the treatment of chronic chest pain in the first place, but was subsequently used as rescue therapy in acute post-thoracotomy pain; it has also been tested in upper abdominal surgery, performed bilaterally. Use in four cases of acute post video thoracoscopy pain management has also been described. Recently, some randomized controlled trials have been carried out that showed: greater analgesic efficacy of ESP compared to intravenous multimodal analgesia standard for the treatment of post-operative pain, with less recourse to rescue doses of morphine following laparoscopic cholecystectomy, mastectomy and cardiac surgery. To date, there are no studies that compare its efficacy with other pain relief methods in acute post-thoracotomy pain. The objective of our study is to compare the analgesic efficacy of these two techniques in the control of acute post-thoracotomy chest pain, blockade of erector spinae vs intrapleural intercostal blockade.