We describe the case of a young woman with asthma and confirmed food allergy to sesame who had 2 severe systemic reactions after the inadvertent ingestion of tahini, a paste made with ground sesame seeds that is not generally known by physicians and patients as a sesame-containing food. A double-blind placebo-controlled food challenge confirmed the allergy to tahini in our patient. As new products and recipes are being introduced from around the world on a regular basis, it is essential that at-risk patients are able to obtain information about allergens used as ingredients and as potential contaminants. This should be applied not only to packaged food but also to freshly made foods, such as those served in restaurants.