Background: Many people have complications after surgery; some transient, others serious, but all are important to patients. Anaesthesia result in a variety of metabolic and endocrine responses, but conventional wisdom maintains that anaesthetic technique has little long–term effect on patient outcomes. There is accumulating evidence that, on contrary, anaesthetic management may in fact exert a number of longer–term effects in postoperative outcome. Objectives: To study the incidence of postoperative complications in relation to age, sex and other factors which influence them and to study correlation of post–operative complications with the nature of anaesthesia, duration of operation, type of surgery and in surgery above diaphragm or below diaphragm. Material and Methods: A prospective study of early post–operative complication in 100 patients’, who underwent major surgery, was done in the Department of Anesthesia in a tertiary care teaching hospital, Unnao. Results: The incidence of post–operative complications was more in patients operated with general anaesthesia (50% and 14% respectively) the morbidity and mortality in patients who were operated under spinal anaesthesia was lower than general anaesthesia, but morbidity was higher in patients who were operated under epidural anaesthesia, but mortality was higher than epidural. Conclusion: There is accumulating evidence that anaesthetic management may indeed exert a number of influences on longer term postoperative outcomes. Further prospective, randomized, large scale, human trials with long– term follow–up are required to clarify the association between anaesthesia technique and postoperative outcome.