In a previous study, we had shown that anastomoses established in the 24(th) hour of reperfusion healed less than the ones established in earlier periods. In this study, we aimed to assess the impacts of polyethyleneglycol-superoxide dismutase (PEG-SOD), a free oxygen radical scavenger and of pentoxyfilline, a methyl-xanthine derivative on anastomotic healing at 24(th) hour of reperfusion. 18 Wistar-albino rats were divided into 3 groups (n=6). In all groups superior mesenteric artery was occluded for 40 minutes and the intestine was reperfused for 24 hours. Rats were relaparotomized in the 24(th) hour and small intestinal anastomoses were established. In Sham group, saline (0.5ml); in Group PTX, pentoxyfilline (25mg/kg); and in Group PGS, PEG-SOD (1500U/kg) was administered intravenously 20 minutes before anastomoses. In the 5(th) day, anastomotic healing was evaluated by bursting pressures and hydroxyproline contents. Results were analized by Mann-Whitney U test, p<0.05 was considered significant. Both of average bursting pressures and average hydroxyproline contents were highest in Group PGS (240 mmHg+/-23.9; 7.71+/-0.68 4mol/g-tissue), followed by sham group (168.3+/-18.3 mmHg; 5.94+/-0.62 mumol/g-tissue) and Group PTX (83.8+/-9.2 mmHg, 5.94+/-0.62 mumol/g-tissue). Differences of these two parameters between all groups were statistically significant (p<0.05). Best anastomotic healing in the 24th hour of reperfusion was achieved by PEG-SOD administration, whereas pentoxyfilline did not favor the healing.