Many prognostic factors of grade-3 primary graft dysfunction at postoperative day 3 (PGD3-T72) have been reported, but intraoperative blood lactate level has not been studied. The present retrospective study was done to test the hypothesis that intraoperative blood lactate level (BLL) could be a predictor of PGD3-T72 after double-lung transplantation.Retrospective monocentric cohort study.Foch University Hospital, Suresnes, France.Patients having received a double-lung transplantation between 2012 and 2019. Patients transplanted twice during the study period, having undergone a multiorgan transplantation, or cardiopulmonary bypass, and those under preoperative extracorporeal membrane oxygenation, were excluded.None.Analysis was performed on a cohort of 449 patients. Seventy-two (16%) patients had a PGD3-T72. Blood lactate level increased throughout surgery to reach a median value of 2.2 (1.6-3.2) mmol/L in the No-PGD3-T72 group and 3.4 (2.3-5.0) mmol/L in the PGD3-T72 group after second lung implantation. The best predictive model for PGD3-T72 was obtained adding a lactate threshold of 2.6 mmol/L at the end of surgery to the clinical model, and the area under the curve was 0.867, with a sensitivity = 76.9% and specificity = 85.4%. Repeated-measures mixed model of BLL during surgery remained significant after adjustment for covariates (F ratio= 4.22, p < 0.001 for interaction).Blood lactate level increases during surgery and reaches a maximum after the second lung implantation. A value below the threshold of 2.6 mmol/L at the end of surgery has a high negative predictive value for the occurrence of a grade-3 primary graft dysfunction at postoperative day 3.