The aim of this study was to investigate the effect of tenoxicam as a non-steroidal anti-inflammatory drug (NSAID) on intra-abdominal adhesion prevention in a rat model. Altogether 50 Wistar-Albino rats weighing 220 - 280 g were assigned to five groups, each of which was made up of 10 rats. All the rats were anaesthetized and prepared for sterile surgery. After a mid-line laparotomy was performed, a 1 cm area of the caecum was rubbed with gauze until subserosal haemorrhage developed, and then a 5 mm-diameter part of the peritoneum on the right side of the abdominal wall was removed. Prior to complete closure, 3 ml of the test material was placed into the abdominal cavity. On the eighth day the rats were killed and the adhesion score was determined. The groups and their mean adhesion scores were as follows: control group (normal saline), 2.5; group of dilution buffer, 1.8; tenoxicam (0.125 mg/kg), 1.3; tenoxicam (0.25 mg/kg), 1.3; and tenoxicam (0.5 mg/kg), 0.9. The differences between the adhesion scores among all the groups (P < 0.05, Kruskal-Wallis test), and those between the tenoxicam groups and control group (P < 0.05, Mann-Whitney U-test), were significant. Thus a single instillation of tenoxicam into the peritoneal cavity at the time of surgery reduced adhesion formation effectively in this model, irrespective of dosage.