Background: Citrus jabara is a type of citrus fruit originally grown in Kitayama-Mura in Wakayama, Japan, and is reputed to have anti-allergic properties. In this study, we tested whether citrus jabara juice inhibits inflammatory mediators in a mouse allergic asthma model. Methods: Mice were sensitized and challenged with ovalbumin to induce chronic airway inflammation. Two groups were orally administered citrus jabara juice at a daily dose of 10 mg/ml or 100 mg/ml in sterile water from day -3 to day 28. Results: Administration of citrus jabara juice significantly reduced the numbers of infiltrating inflammatory cells in bronchoalveolar lavage fluid, as compared to control mice. Histopathological studies of the lung using hematoxylin & eosin and periodic acid-Schiff staining showed that citrus Jabara juice inhibited inflammatory cell infiltration and mucus hypersecretion in ovalbumin-challenged mice. In addition, the juice reduced levels of IL-4 while increasing levels of INF-?. Conclusions: These findings provide new insight into the immunopharmacological effects of citrus jabara and suggest its potential in supportive therapies for asthma.