The negative effects of ischemia-reperfusion injury (IRI) on intestinal anastomotic healing have been described in previous studies. To determine the effect of pentoxifylline (PTF) on small-bowel anastomoses performed after IRI, 20 male Wistar albino rats were studied. Under ketamine anesthesia, the superior mesenteric artery was occluded for 30 min and ileal resection-anastomosis was performed after 10 min of reperfusion. In group I, no medication was given. In group II, PTF 50 mg/kg was administered intraperitoneally before reperfusion and i.m. on the 1st, 2nd, 3rd and 4th postoperative days (POD). All rats were killed and anastomotic segments were removed on the 7th POD. Anastomotic bursting pressure (ABP) and hydroxyproline (HP) content were measured in the anastomotic segments; parameters were compared statistically with Student's t-test. In group I, the mean ABP was 225.5 +/- 38.18 mmHg the and mean HP level was 16.03 +/- 1.91 micro mol/g tissue. In group II, these levels were 277 +/- 41.1 mmHg and 19.85 +/- 1.81 micro mol/g tissue, respectively. The differences between the groups were significant (P < 0.005). Thus, PTF can improve anastomotic healing in an experimental model after IRI by promotion of collagen synthesis.