Objective Changes in serum albumin may reflect systemic immunoinflammation and hypermetabolism in response to insults such as trauma and sepsis. Esophagectomy is associated with a major metabolic stress, and the aim of this study was to determine if the absolute albumin level on the first postoperative day was of value in predicting in- hospital complications. Methods A retrospective study of 200 patients undergoing esophagectomy for malignant disease at St. James Hospital between 1999 and 2005 was performed. Patients who had pre and postoperative ( days 1, 3, and 7) serum albumin levels measured were included in the study. Patients were subdivided into three postoperative albumin categories < 20 g/ l, 20 - 25 g/ l, > 25 g/ l. Logistic regression analysis was performed to calculate the odds of morbidity and mortality according to the day 1 albumin level. Results Patients with an albumin of less than 20 g/ l on the first postoperative day were twice as likely to develop postoperative complications than those with an albumin of greater than 20 g/ l ( 54 vs 28% respectively, p< 0.011). Correspondingly, these patients also had a significantly higher rate of Adult Respiratory Distress Syndrome ( 22 vs 5%, p< 0.001), respiratory failure ( 27 vs 8%, p< 0.01) and in- hospital mortality ( 27 vs 6% ( p< 0.001). On multivariate logistic regression analysis, day 1 albumin level was independently related to postoperative complications ( odds ratios, 0.89: 95%; confidence intervals, 0.83 - 0.96; p< 0.005). In addition, albumin < 20 g/ l on the first postoperative day was associated with the need for further surgery and a return to ICU. Conclusion Serum albumin concentration on the first postoperative day is a better predictor of surgical outcome than many other preoperative risk factors. It is a low cost test that may be used as a prognostic tool to detect the risk of adverse surgical outcomes.