Introduction The severity of allergic reactions during oral food challenges (OFC) is difficult to predict, and to date, predictive factors have not been well established. Methods We reviewed data of children who reacted during IgE-mediated food challenges from an 18 month period. Linear regression analyses, chi-squared test, and t-test were conducted to investigate the relationship between patient demographics, skin tests, atopic status and reaction severity. Severity of reactions was assessed by modified Bock score. Severe reactions were defined as those scoring ≥2 points in either target organ of lower respiratory tract or cardiovascular/neurologic. Results 202 challenges were reviewed. 32 challenges (15.8%) met criteria for severe reaction. Age, skin test wheal and flare, cumulative dose, and presence of asthma were not significant predictors of total Bock score (p=0.27, p=0.45, p=0.11, p=0.18, p=0.13 respectively) and these factors were not statistically different between patients with severe reactions compared to those without (p=0.90, p=0.35, p=0.87, p=0.77, p=0.17). When assessing foods, egg had a lower rate of severe reaction than predicted, and sesame a higher rate, though differences were not significant (p=0.26). Conclusions In our review of OFC for IgE-mediated food allergy, patient demographics and allergy testing were poor predictors of reaction severity. The severity of allergic reactions remains largely unpredictable and severe reactions can occur in patients of all ages. Food was not a statistically significant predictor, but additional challenge data may help identify foods that are associated with a higher risk of severe reaction. The severity of allergic reactions during oral food challenges (OFC) is difficult to predict, and to date, predictive factors have not been well established. We reviewed data of children who reacted during IgE-mediated food challenges from an 18 month period. Linear regression analyses, chi-squared test, and t-test were conducted to investigate the relationship between patient demographics, skin tests, atopic status and reaction severity. Severity of reactions was assessed by modified Bock score. Severe reactions were defined as those scoring ≥2 points in either target organ of lower respiratory tract or cardiovascular/neurologic. 202 challenges were reviewed. 32 challenges (15.8%) met criteria for severe reaction. Age, skin test wheal and flare, cumulative dose, and presence of asthma were not significant predictors of total Bock score (p=0.27, p=0.45, p=0.11, p=0.18, p=0.13 respectively) and these factors were not statistically different between patients with severe reactions compared to those without (p=0.90, p=0.35, p=0.87, p=0.77, p=0.17). When assessing foods, egg had a lower rate of severe reaction than predicted, and sesame a higher rate, though differences were not significant (p=0.26). In our review of OFC for IgE-mediated food allergy, patient demographics and allergy testing were poor predictors of reaction severity. The severity of allergic reactions remains largely unpredictable and severe reactions can occur in patients of all ages. Food was not a statistically significant predictor, but additional challenge data may help identify foods that are associated with a higher risk of severe reaction.