AbstractIntroduction: General anaesthesia predisposes a patient to regurgitation andaspiration of gastric substances into otherwise healthy lungs leading to fatal acidaspiration syndrome. Historically, the syndrome most commonly described as aspiration pneumonitis or Mendelson’s syndrome, 1 was reported in 1946 in patientswho aspirated while receiving general anaesthesia during obstetrical procedure. Everypracticing anaesthesiologist thus has a key concern to this preventable devastatingclinical condition which causes progressivelung damage due to the acidic solution. Methods: This is a prospective, controlled, randomised, single blinded studyconducted in 60 patients of American Society of Anaesthesiologists grade I and IIposted for elective surgery under general anaesthesia. The patients enrolled in thestudy were randomly assigned to two groups having 30 patients in each. Group Preceived i.v pantoprazole 40mg, Group E received i.v esomeprazole 40 mg a nightprevious to surgery. The observer was totally blind about the groups or drugs given tothe patients. On the day of surgery, after induction of anaesthesia gastric juice wasobtained via nasogastric tube and was checked for pH using pH meter. Results: Mean pH of group P was 5.15± 0.68 which is significantly lower thangroup E, who received i.v esomeprazole sodium with mean pH of 6.6±0.67, (P<0.001), as shown by two-tailed independent T test. Conclusion: From the observations and analysis of the present study, it can beinferred that esomeprazole sodium 40 mg i.v is more effective than pantoprazole 40mg i.v to raise the gastric pH for prevention of aspiration pneumonitis.