OBJECTIVE To assess postoperative pain intensity and the analgesic requirements in the postoperative period in patients undergoing sternotomy for pulmonary endarterectomy involving deep hypothermic circulatory arrest. METHODS Retrospective cohort study. METHODS Single-center hospital study. METHODS Patients 18 years and older undergoing sternotomy for cardiac surgery between August 2012 and August 2014. METHODS No modification to usual clinical practice. RESULTS Intraoperative opioid and steroid administration, referral to the chronic pain unit, intensive care unit pain scores, and analgesic administration in the first 48 hours after the admission to the intensive care unit were recorded. Postoperative pain was evaluated by means of a categoric verbal scale from no pain (0) to severe pain (3); this is the routine analgesic scale used in the authors' intensive care unit. A total of 200 consecutive patients undergoing pulmonary endarterectomy (PEA group) were included in the study. No patient in the PEA group received morphine during surgery. The mean (standard deviation) postoperative pain intensity score at 24 hours was 0.30 (0.54) in the PEA group. Postoperative morphine was administered in 39% of patients. No PEA patient was referred to the chronic pain unit after hospital discharge. CONCLUSIONS The total analgesic requirements and pain score of patients undergoing sternotomy for pulmonary endarterectomy with deep hypothermic circulatory arrest seemed to be low.