OBJECTIVE Intra-abdominal adhesions typically occur after surgically damaged tissues are situated in apposition, leading to fibrotic connections. The goal of this study was to demonstrate the in vivo efficacy of a cross-linked and insoluble hyaluronic acid (HA) film to reduce postsurgical adhesion in a rat model. METHODS To measure in vitro adhesion resistance, porcine monocytes were deposited on the surface of films and their attachment was monitored by scanning electron microscopy. A rat cecum abrasion and abdominal insult model was utilized to demonstrate in vivo efficacy. Briefly, an HA film was deployed as a barrier between the damaged cecal and abdominal tissue surfaces for 21 days; control animals did not receive treatment. At the study conclusion, the rats were sacrificed and the degree of adhesion was determined using a scale from 0 to 3, where 0 = no adhesion and 3 = severe fibrosis. RESULTS HA films resisted monocyte adhesion in vitro. The in vivo study results demonstrated a significantly lower mean adhesion score (0.625 +/- 0.517) with HA film treatment compared to the controls (2.09 +/- 1.22). CONCLUSIONS Placement of HA films between injured tissues significantly decreases the severity of abdominal adhesions. Furthermore, the HA film's resistance to monocyte adhesion could be contributory to lowering in vivo adhesion scores.