Sanguisorba officinalis L. is known to have anti-inflammatory properties. However, the potential effects of S. officinalis against asthma have not been reported. In the present study, we investigated the protective effects and underlying mechanisms of S. officinalis in a murine ovalbumin (OVA)-induced asthma model. Mice were sensitized and challenged by OVA inhalation to induce airway inflammation and remodeling. S. officinalis ethanolic extract (SOEE) markedly decreased the number of infiltrated inflammatory cells, together with a reduction in the levels of T-helper type 2 cytokines and immunoglobulin E levels. Histopathological studies showed that inflammatory cell infiltration and mucus hypersecretion were inhibited by SOEE. In addition, OVA-induced increases in reactive oxygen species were attenuated by SOEE. All these effects were correlated with heme oxygenase-1 (HO-1) induction by SOEE. These results indicate that SOEE has therapeutic potential against bronchial asthma associated with allergic diseases that is due, at least in part, to HO-1 upregulation.