Background: Airway management is a fundamental aspect of anaesthetic practice. Difficult airway is considered as a night mare. Failure to secure a definitive airway has led to catastrophic consequences. Such events are preventable with an adequate assessment, orientation, systematic preparedness. Cormack & Lehane’s grading of direct larnygoscopic view is considered as benchmark for grading of difficult intubation. Taking Cormack & Lehane grading system to assess difficult intubation we evaluated few non-invasive tests as predictors of difficult airway. So we decided to conduct a prospective observational study, comparing the simple bedside screening tests that can help to accurately predict difficult endotracheal intubation. Materials & Methods: After obtaining institutional ethical committee clearance and written informed consent from every patient, a total of 362 patients were recruited as per the predetermined inclusion and exclusion criteria in this study. Preoperatively airway was assessed by Investigator in terms of Mallampatti score, ratio of height to thyromental distance, inter-incisor gap, upper lip bite test and hyomental distance and documented. And direct laryngoscopy was done by senior anaesthesiologist who was not apprised of the pre-operative measurements of the study tests during induction of anaesthesia and was graded according to Cormack & Lehane classification. The ability of the test to predict difficult intubation was calculated in terms of sensitivity, specificity, positive and negative predictive value and eventually accuracy of the tests were calculated. Statistical analysis was performed using SPSS Version 15.0. Results: Incidence of difficult intubation was 4.7% defined by comark lehane grade 3 and4. RHTMD had the best 70.58% sensivity, 99.13% specificity, 80.00% positive predictive value, 98.55% negative predictive value. With overall accuracy of 97.79%. Where as other non-invasive tests showed a better specificity and negative predictive value than sensitivity and positive predictive value. Conclusion: Ratio of height to thyromental distance was found to be better predictor of difficult endotracheal intubation. And the rest other non-invasive tests were not a better predictor of difficult intubation.