Background: The fundamental responsibility of anesthetist is to maintain the airway and provide adequate oxygenation. Failure to do this will lead to hazardous complication. So identification of difficult airway is important during pre operative evaluation. Difficult intubation can be predicted by modified mallampati test (MMP), inter­incisor distance, thyro­mental distance (TMD), sterno­mental distance, upper lip bite test and hyo­mental distance ratio, but no single factor reliably predicts difficult intubation. AASI, a relatively new test, based on surface land mark, has been suggested to reliably predict difficult visualization of larynx. Methods: A total of 250 adult patients, of either sex, aged 18­ 65 years, belonging to ASA class 1, 2 and 3 who were candidates undergoing elective surgery under general anaesthesia requiring tracheal intubation participated in a prospective, comparative, observational study. Preoperative airway assessment was carried out with AASI, TMD and MMP. Sensitivity, specificity, positive predictive value, negative predictive value, odd’s ratio, positive likelihood ratio, negative likelihood ratio were calculated for MMP, TMD and AASI. Chi­square test was used to analyze data. P value of less than 0.05 was considered
statistically significant. Results: The demographic data was normally distributed in terms of age, height, weight, bmi, and gender distribution. The sensitivity between MMP and TMD was statistically significant. There was no significant difference between the Specificity, positive predictive value & negative predictive value of MMP and TMD (p>0.05). There was no significant difference between the Sensitivity, Specificity, positive predictive value & negative predictive value of MMP and AASI. (p>0.05) There was significant difference in Sensitivity of TMD & AASI. But, there was no significant difference between the Specificity, Positive predictive value & Negative predictive value between TMD and AASI. Conclusion: Upon comparing AASI, MMP and TMD, AASI was found to be better only with regards to sensitivity no difference in any of the measured parameters in comparison to modified mallampati test. To conclude we would recommend further studies with larger sample size before validating or refuting the ASSI.