The current study was designed to investigate the efficacy of a hyaluronate/carboxymethylcellulose membrane for the prevention of post-operative adhesion in a rat uterine horn model. This is a prospective double-blinded controlled study. Nineteen injured uterine horns were treated with a hyaluronate/carboxymethylcellulose membrane as a barrier and 19 injured uterine horns without any treatment served as a control group. Two weeks later, second look laparotomies were performed in order to assess the degree of the adhesion. Total adhesion scores, histopathological analysis of inflammation process and vascularization of adhesions were compared with control group. P values of 5% or less were considered statistically significant. Animals treated with a hyaluronate/carboxymethylcellulose membrane had significantly reduced post-surgical adhesion scores when compared with control group. In histopathological examination, there was less vascularization in the treatment group. The types and extent of inflammation were similar in two groups. Clinically and histopathologically, a hyaluronate/carboxymethylcellulose membrane is effective in reducing postoperative adhesion formation in the rat uterine horn model. (C) 2004 Tohoku University Medical Press.