Octreotide, a long-acting somatostatin analogue, is widely used in gastrointestinal hypersecretory states and also for endocrine tumors in an attempt to inhibit the paracrine hormones. Although it is well known that octreotide inhibits trophic and anabolic hormones, no research has been conducted on its adverse effects on wound healing. In the present study, groups of rats were given 20 mcg/kg/day octreotide and 100 mg/kg/day hydrocortisone, the latter being the negative control group, starting 5 days preoperatively. The colonic anastomoses were assessed for healing on postoperative days (PODs) 5 and 8 by determining the bursting pressure of the anastomoses, performing histopathological analysis, and measuring the hydroxyproline content of the anastomotic tissues. Octreotide was found to affect anastomotic healing negatively on both PODs 5 and 8, but the negative effect of hydrocortisone was significant only on POD 8. No significant difference was found between the adverse effects of the two agents on POD 8. These findings indicated that octreotide has an adverse effect on the healing of colonic anastomoses in rats.