In this study, the effect of an aqueous extract of Rumex patientia L. (Polygonaceae) (D-1) on capillary permeability which was induced by xylol and hyaluronidase was investigated. Experiments were conducted on rabbits according to Monakova and Matusis methods. The effects of D-1 were compared to those of indomethacin, which was used as a control throughout the experiment. Both D-1 (100 mg/kg) and indomethacin (10 mg/kg) were administered orally. As a result, D-1 inhibited capillary permeability, which was induced by xylol and hyaluronidase, and it was found that it was as effective as indomethacin.