Objective: Alliumcepa is often used in traditional African medicine for the management ofmany pathologies. Therefore, our objective was to study the anti-histaminic effect of the aqueous extract of Alliumcepa in mice. Material and Methods: Allergy was previously induced in mice by administration of an allergic solution (0.15 ml egg white, 0.05 ml maalox and 0.05 ml NaCl) intraperitoneally. The antiallergic effect of the Total Aqueous Extract (TEA) of Alliumcepa leaves was evaluated by observing the number of scratching in allergic mice treated orally with different doses (250 and 500 mg/kg of body weight) of this extract. Results: The phytochemical study revealed the presence of polyterpenes, sterols, polyphenols, flavonoids, tannins, quinone and alkaloids but also the absence of saponosides. The acute toxicity study at the single dose of 2000mg/kg CP orally revealed that the aqueous extract of Alliumcepa is not toxic and would have an oral LD 50 greater than or equal to 5000mg/kg CP. After oral administration of the extarit, we observe a reduction in the number of scratching in allergic mice. Conclusion: These results show that Alliumcepa bulbs have an anti-allergic activity, which would justify its use in African traditional medicine to prevent or treat allergy.