Background :ARISCAT (Assess Respiratoryrisk In Surgical patients in CATolonia) is a 7 variable index classifying the patients into mild, moderate and high risk for postoperative pulmonary complications. Components of score include age,preoperative SpO2,respiratory infection in last month,preoperativ e anaemia,surgical incision,duration of surgery,emergency procedure.However this index is derived from population of only one particular geographical area(Catolonia ,Spain).There are only few prospective studies of this risk score in our geographic population. AIM and OBJECTIVES: To study the risk of post operative pulmonarycomplications in patients undergoing elective or emergency surgeries using ARISCAT score • To find out the incidence of post operative pulmonary complications in various surgeries • To calculate sensitivity and specificity of ARISCAT score METHODOLOGY : This is a prospective observational study done in a teritiary care hospital in 100 patients refered to pulmonology department for preoperative evaluation from sept 2023 to NOV 2023.They we re assessed with ARISCAT score preoperatively and followed up postoperatively for any complications. RESULTS : Out of 100 patients studied, 38 were predicted as low risk,4 1 were predicted as intermediate risk and 21 as high risk to develop postoperative pul monary complications. 80.9% predicted as high risk with ARISCAT score developed postoperative pulmonary complication,31.7% predicted as intermediate risk and 11.7% predicted as low risk developed postoperative pulmonary complications. Senstivity of ARISCAT score is 53% and specificity is 93.9 % in our study. CONCLUSION : ARISCAT score can be used in preoperative evaluation to assess the risk for postoperative pulmonary complications with a specificity of 93.9% Postoperative pulmonary complications have higher incidence in our study and is responsible for increased length of stay in hospital.