Introduction: The surgical outcome is always influenced by postoperative respiratory complications. In few cases post-operative mechanical ventilation is needed while undergoing surgeries with general anaesthesia. There are many postoperative and intraoperative parameters are responsible for this. This study was designed to assess the association of pre and intra operative parameters with post-operative mechanical ventilation in cases subjected to elective abdominal surgery. Materials and methods: A total 100 cases scheduled to undergo elective major or minor abdominal surgeries between age group 21-70 years were recruited. Cases were administered with general anesthesia and cases were scheduled for extubation at the end of surgery, but complicated cases were shifted to ICU for post-operative mechanical ventilator support. Peak expiratory flow rates were measured in those extubated within 24 hrs after surgery. Results: Low albumin levels, alcohol consumption, preoperative hospital stay, preoperative respiratory tract infection, COPD, bronchial asthma, obstructive sleep apnea, Sputum production, smoking were not statistically significant and pre-operative hospitalization time, Smoking, >10% weight loss, Hypertension, ischemic heart diseases, cerebrovascular complication were significantly correlating with postoperative mechanical ventilation. Conclusion: Significant parameters such as <10% weight loss, pre-operative hospitalization and smoking found to be significant parameters of requirement of post-operative mechanical ventilation by multiple logistic regressions