Postoperative formation of adhesions is a common complication in abdominal surgery. The aim of the present study was to develop standardized experimental models for quantitative studies of the formation of adhesions in rats and rabbits. In rats the suturing of a peritoneal wound increased adhesion formation significantly compared to leaving it open, 77.9 +/- 4.8 and 5.3 +/- 2.8%, respectively (p < 0.001). The suturing technique, when comparing the interrupted and continuous method after 1 week, had no influence, 84.5 +/- 6.3% and 73.1 +/- 11.2%, respectively (p > 0.05). Different types of trauma resulted in differences in adhesion formation to noninjured parts in the abdominal cavity, adhesions in 17.5 and 2.5% of the animals, respectively (p < 0.05). In rabbits adhesions formed more frequently (p < 0.001) to visceral peritoneum (59.3 +/- 3.7%) than to the parietal one (22.3 +/- 1.6%) indicating a different propensity of tissues to have adhesions. These models enable detailed quantitative studies on experimental formation of adhesions.