Introduction: The development of early extubation protocols in cardiac surgery are based on anesthesic techniques able to have the appropriate anesthesia depth and a secured airway during the emergence of anesthesia. A prospective study was design in adults subjected to cardiac surgery in order to evaluate the effectiveness of preoperative bilateral paravertebral thoracic block (BPVTB) in decreasing intraoperative opiods doses and allow a safe extubation in the operating room (OR) and, even more, give a good quality postoperative (PO) analgesia. Material and Methods: Patients subjected to a cardiac surgery with sternotomy. Exclusion criteria were: long and complex surgery, circulatory arrest, deep hypothermia, cardiac failure, severe pulmonary hypertension, obesity grade II or greater, severe lung disease and coagulophaty. A cohort of patients were subjected to a BPVTB, then general anesthesia was induced (no standarized technique). After cardiac surgery, at the beginning of skin suture, inhaled anesthetics were discontinued and after successful spontaneous breathing test, the patient was extubated in the operating room. PaO2 y PaCO2 was evaluated at the arrival to the ICU. Visual analogue scale (VAS) was applied every 6 hours to measure pain level. At the end of the first day opiod dose, PONV and ventilation support (invasive and no invasive) was registered. Results: 43 patients were included. There were 2 losses (4.6%) in the OR. Within de preoperative variables, median age was 65 years; 58% pacients were males. The surgeries were as follow: 34 Coronary Artery Bypass Graft Surgery (CABG), 2 combined surgeries (CABG and valvular), 2 aortic valve replacement, 2 resections of left atrial myxomas and 1 atrial septal defect closure. The time in the operating room (anesthesia plus surgery) and the time on cardiopulmonary bypass (CPB) had a median of 240 and 78 minutes respectively (12 patients had offpump). Every patient received midazolam with a median dose of 2.25 mg; 85% of patients received fentanyl, 297 μg per patient in average (4.2 μg kg-1 y 1.1 μg kg-1 h-1), 15% of patients received remifentanil with target control infusion. In 40 patients (97,5%) extubation was successfully achieved in the OR. Of these 40 patients the arterial blood gases showed a PaFiof 208 and a PaCO2 of 41 mmHg. VAS at 6 hours PO was 2,25 (resting) y de 3.75 (dynamic). 19 patients required some opioid rescue during the first 24 hours. 8 patients had PONV during the first 24 hours. No patient required ventilatory support or reintubation. Conclusions: The use of BPVTB admit a low intraoperative opioid dose, allowing an early and safe extubation after cardiac surgery. BPVTB gives good quality analgesia during the first 6 PO hours after a sternotomy.