Cubebin, a dibenzylbutyrolactone lignan isolated from the crude hexane extract of the leaves of Zanthoxyllum naranjillo, showed a significant anti-inflammatory activity by using the paw edema induced by carrageenin in rats, but did not provide a significant reduction in the cell migration for the acute carrageenin-induced inflammatory reaction in the peritoneal cavity of rats. Neither was it effective in reducing the edema induced by dextran nor the edema induced by histamine. It partially reduced the edema induced by serotonin. Moreover, it significantly reduced the edema induced by prostaglandin PGE2 and the number of writhings induced by both acetic acid and PGI2 in mice. Therefore, it may be suggested that the mechanism of action of cubebin is similar to that observed for most of the non-steroidal drugs.