Peanut allergy is the major leading cause of fatal or life-threatening anaphylactic reactions to foods. At present, there is no remedy for this condition. The applied pharmaceutical cares are merely palliative, while their deleterious side effects have already been established. Hence, many sufferers search for complementary and alternative medicines. A versatile-, "flavonol" subgroup-member of the flavonoid family, quercetin, is of paramount interest to investigators. In this study the effects of quercetin on peanut-induced anaphylactic reactions were investigated in a rat model of peanut allergy. Wistar rats were sensitized with crude peanut extract in the presence of Cholera toxin and Aluminium hydroxide. Sensitized rats were then allotted into three groups; Positive control, Quercetin-treatment and Sham, (n=7, each). Naive rats (n=7) served as negative controls. One week post-sensitization period, the rats in treatment group were treated with quercetin at a dose of 50 mg/kg(Body Weight)/mL Di-methyl-sulfoxide 5%/rat, over a period of four weeks. Subsequently, rats were challenged, and anaphylactic reaction parameters including variations in plasma histamine levels, vascular permeability, systemic anaphylaxis scores, and total serum Immunoglobulin E levels were measured. After daily-gavaging for four weeks, quercetin completely abrogated peanut-induced anaphylactic reactions following challenges, so that the mean of plasma histamine levels in the quercetin-treated rats, were lower significantly (p=0.004) as compared with positive control group. Our findings suggest that the flavonoid quercetin is potent enough to suppress the on-going Immunoglobulin E responses against peanut proteins, and can be propounded as an alternative medicine to protect against Immunoglobulin E-mediated food allergies.