Background:The benefits of laparoscopy as compared to open surgery, include reduced postoperative pain, minimal scarring, quick recovery, and short convalescence. The present study was conducted to compare physiological changes between transperitoneal and retroperitoneal approach for urologic laparoscopic surgery. Materials & Methods:50 healthy individuals undergoing elective urologic laparoscopic surgeries of both genderswere divided into 2 groups of 25 each divided into two groups according to the surgical approach used. Group I patients underwent transperitoneal (Trans) and group II underwent retroperitoneal (Retro) approach.Compliance, peak inspiratory pressure (PIP), minute ventilation (MV), heart rate (HR) and mean arterial pressure (MAP) were monitored at defined time interval. Arterial blood gases were also measured to compare partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2 /FiO2) ratio. Results:The mean age was 42.5±2.3 years in group I and 46.2±4.2 years in group II. The mean weight was 57.4±7.5 kgs in group I and 53.1±7.6 kgs in group II. Duration of surgery (mins) was 254.2±17.4 in group I and 202.8±14.5 in group II. Lateral positions (right/left)was seen in 14:11 and 10:15 and duration of CO2 insufflation (mins) was 192.4±18.3 in group I and 170.6±12.1 in group II. The difference was non- significant (P> 0.05). Surgery performed were simple nephrectomy in 12 and 10, donor nephrectomy in 0 and 7, partial nephrectomy in 0 and 2, radical nephrectomy in 8 and 2, pyeloplasty in 5 and 0 and ureterolithotomy in 0 and 4 in group I and II respectively. The difference was significant (P< 0.05).P/F ratio at baseline was 394.2±11.5 and 400.5±24.1, P/F ratio at the end was 430.5±25.2 and 352.4±37.4, PaCO2 -EtCO2 difference at baseline was 4.7±1.1 and 4.2±1.9 and PaCO2 -EtCO2 difference at the end was 6.3±2.3 and 8.1±2.1 in group I and II respectively. The difference was significant (P< 0.05). Conclusion: Respiratory and haemodynamic parameters are stable and comparable between the two approaches.