Fibrin glue inhibits intra-abdominal adhesion formation. To determine the effect of fibrin glue on intra-abdominal adhesion formation, 45 rats were randomized to three groups. Each animal received two adhesion models. Group 1 received no further treatment. Groups 2 and 3 had the adhesion models covered with fibrinogen from fresh frozen plasma (1.77 g/L) and cryoprecipitate (23.6 g/L), respectively. In group 1, 13 of 15 rats had high-grade adhesions in both models. In group 2, high-grade adhesions were noted in nine of 15 rats in model 1 and in 12 of 15 rats in model 2. In group 3, however, high-grade adhesions were seen in only three of 15 rats in model 1, with 11 rats having no adhesions, and in only two of 15 rats in model 2. Histologic analysis suggested accelerated healing in group 3. We conclude that (1) fibrin glue inhibits intra-abdominal adhesion formation in rats, (2) the inhibitory action is dependent on the fibrinogen concentration of the fibrin glue, and (3) adhesions are reduced by fibrin glue regardless of whether the peritoneal defect is closed. 