The isolation for the first time from Artemisia judaica L.(Compositae) of the known flavone, cirsimaritin (5, 4′-dihydroxy-6, 7-dimethoxyflavone), its identification, and its biological effects on the isolated guinea-pig ileum are described. Small concentrations (2× 10-6 M to 2× 10-5 M) of cirsimaritin have no observed effects on the phasic contractions or the tone of guinea-pig ileum. Larger concentrations (up to 3× 10-4 M), however, cause a concentration-dependent inhibition of the amplitude of the phasic contractions and reduce the tone of this preparation. Cirsimaritin also causes a shift to the right in the concentration-effect curves of histamine, acetylcholine, and BaCl 2 on guinea-pig ileum. The maximum contractions induced by the above agents are inhibited by 35.5%, 47.6%, and 79.5%, respectively. These data support the use of A. judaica L. in folk medicine for certain gastrointestinal disorders.