Background: Laparoscopy has been used as a therapeutic as well as a diagnostic tool in pelvic and abdominal surgeries. Present study was aimed at to study correlation of acid base and blood gas changes during laparoscopy and effects of various insufflating agents comparing Carbon Dioxide with Nitrous Oxide at a tertiary care hospital. Material and Methods: Present study was hospital based, comparative study, conducted in female patients from age group of 20-40 years in ASA Class – I/II undergoing diagnostic laparoscopy and laparoscopic tubal ligation. Results: We compared effects of pneumoperitoneal insufflating agents among 2 groups of 35 patients each as Group N (Nitrous oxide as the insufflating agent) versus Group C (carbon dioxide as the insufflating agent). The blood gas analysis showed a rise in PaO2 and O2 saturation, due apparent rise mainly to the FiO2. Though the PaO2 is adequate to meet the increase in the tissue oxygen demand, it is inconsistent with the FiO2 (33%) delivered. The post operative and oxygen saturation came back to their pre-operative values. The PaCO2 was significantly higher intra-operatively in both the groups, with numerically high values in Group C. The PeCO2 followed the trend of PaCO2 and the fall of pH was consistent with the rise in PaCO2. Though the rises of the PaCO2 and fall in pH were statistically significant, they did not reach hazardous level. Group N (14.28 %) had more incidences of nausea and vomiting as compared to Group C (5.71 %). Conclusion: Nitrous oxide appears to be the most suitable insufflating agent, used to produce pneumoperitoneum as compared to carbon dioxide, with general anaesthesia for laparoscopic surgeries.