Background: Thiol/disulfide homeostasis is a significant parameter in determining the oxidative stress response after ischemia and reperfusion. We aimed to investigate the effects of applying different intraabdominal pressure (IAP) on thiol/disulfide homeostasis, ischemia-modified albumin (IMA) levels, and hemodynamics in pediatric laparoscopic surgery. Materials and Methods: Blood samples were collected from 36 pediatric patients who were planned to undergo laparoscopic surgery for nonpalpable testis or varicocele under general anesthesia, immediately after intubation as the baseline and 5 minutes after abdominal desufflation for determining the thiol/disulfide, and IMA levels. The patients were divided into two groups; group 1 received a pneumoperitoneum pressure of 8mm Hg (n=18), and group 2 received 12mm Hg (n=18). The clinical characteristics and thiol/disulfide homeostasis and IMA levels of the patients were compared. Results: No difference was detected regarding the clinical features between the groups. The comparison after intubation and after desufflation in group 1 demonstrated lower native thiol (45367 versus 422 +/- 57mol/L, P=.059) and total thiol (497 +/- 73 versus 466 +/- 62mol/L, P=.061) levels, which was statistically insignificant. The serum native thiol level was found lower than baseline in group 2 where a 12mm Hg IAP was applied, this difference was not statistically significant (429 +/- 47 versus 412 +/- 53mol/L, P=.078). The comparison of serum IMA levels after desufflation with the baseline (0.505 +/- 0.018 versus 0.632 +/- 0.022) in group 2 was found statistically significantly high (P=.031). The comparison of the perioperative heart rate and SpO(2) levels with before induction was found statistically insignificant. Conclusions: Neither of 8 nor 12mm Hg IAPs in pediatric laparoscopic surgery caused any changes in novel indicators of thiol/disulfide homeostasis parameters; however, 12mm Hg IAP increased the levels of IMA.