Inflammation of the respiratory tract is a crucial process in immune diseases, including asthma, and atopic rhinitis. To establish whether an aqueous extract of Spinacia oleracea Linn (SoL) has a beneficial influence in terms of anti-asthmatic activity, we examined its effects on an ovalbumin-induced asthmatic model. Mice sensitized to ovalbumin were orally administered the SoL extract, and their lungs examined by hematoxylin and eosin staining to determine IL-4/13 cytokine expression. The SoL extract exerted strong anti-asthmatic effects by inducing a decrease in the CD4+ cell number, IL-4/13, and other molecular markers in the lung. Our results collectively indicate that the aqueous SoL extract ameliorates asthmatic symptoms effectively in a mouse ovalbumin-challenge model.