Background: Familiarity with Bain’s circuit and flow rate requirements is helpful in emergency situations. AIM: To study the flow rate and respiratory rate requirements before and during pneumoperitoneum. Design: prospective randomised study done in a tertiary care setting. Methods: 30 patients undergoing different laparoscopic surgeries were with bains circuit with flow rate and respiratory rate adjusted to maintain narmocarbia.Statistical analysis : we assume the flow rate and respiratory rate will be the same before and during pneumoperitoneum considering null hypothesis.As the respiratory parameters need to changed to maintain normocarbia during pneumoperitoneum Null hypothesis is rejected. Results: We have to increase the fresh gas flow rate from 80 ml to 100 to 110 ml/kg during pneumoperitoneum and respiratory rate from 12 to 14 to maintain narmocarbia with Bain’s circuit in laparoscopic surgery.