Postoperative peritoneal adhesions are major concerns in abdominal surgery. In this experimental study, the effects of 4 % icodextrin and omega-3 fatty acids (ω-3 FA) on prevention of postoperative peritoneal adhesions were evaluated. Twenty-four Wistar albino rats were divided into three groups. After laparotomy, serosal abrasion was carried out by cecal brushing. Intraperitoneally 3 cm 3 0.9 % NaCl, 3 cm 3 4 % icodextrin, and 200 mg/kg ω-3 FAs for each group were applied, and then the abdomen was closed. All subjects sacrificed 10 days postoperatively. Macroscopic and histopathological cellular reactions as a function of giant cell, lymphocyte/plasmocyte, neutrophil, histiocyte, intracellular adhesion molecule-1 (ICAM-1), and platelet endothelial cell adhesion molecule-1 (PECAM-1) were assessed and hydroxyproline levels were measured in all three groups and compared using Kruskal-Wallis and ANOVA tests when appropriate. Macroscopically, both ω-3 FAs and 4 % icodextrin reduced adhesion formation but the difference was not statistically significant (P00.253). Histopathological examination revealed that there was no statistical significance in terms of giant cell, lymphocyte/plasmocyte, neutrophil, ICAM-1, and PECAM-1 scores; however, both ω-3 FAs and 4 % icodextrin were found to be prone to reduce fibrosis (P00.047), whereas in the ω-3 FA group, histiocytic reaction was significantly increased (P00.001), and hydroxyproline levels were significantly lower than other groups (P00.044). In this study, ω-3 FAs were found to be superior to 4 % icodextrin with the lower hydroxyproline level and greater histiocytic reaction. Considering these results, ω-3 FAs can be a promising agent in the prevention of adhesion formation.