Background: Pulmonary complications are the most frequent cause of postoperative morbidity and mortality in upper abdominal surgery (UAS). We aimed to examine the influence of possible preoperative, operative and postoperative risk factors on the development of early postoperative pulmonary complications (POPC) after UAS. Methods: A prospective study of 60 consecutive patients was conducted who underwent elective UAS in general surgical unit. Each patient's preoperative respiratory status was assessed by an experienced chest physician using clinical examination, chest radiographs, spirometry and blood gas analysis. Anaesthetical risks, surgical indications, operation time, incision type, duration of nasogastric catheter and mobilization time were noted. Forty-eight hours after the operation, pulmonary examinations of the patients were repeated. Results: Postoperative pulmonary complications were observed in 35 patients (58.3%). The most common complication was pneumonia, followed by pneumonitis, atelectasis, bronchitis, pulmonary emboli and acute respiratory failure. The presence of preoperative respiratory symptoms and the spirometric parameter of forced expiratory volume in 1 s/forced vital capacity were the most valuable risk factors for early prediction of POPC. The sensitivity, specificity and diagnostic efficiency of the presence of preoperative respiratory symptoms in the POPC prediction were 70, 61 and 66%, respectively. Conclusion: We recommend a detailed pulmonary examination and spirometry in patients who will undergo UAS by chest physicians to identify the patients at high risk for POPC, to manage respiratory problems of the patients before surgery and also to help surgeons to take early measures in such patients before a most likely POPC occurrence. Improvement of lung function in those patients at risk for POPC before operation may decrease morbidity in surgical patients. © 2007 Royal Australasian College of Surgeons.