Background Legumes, and particularly lentils, are frequently consumed in Mediterranean, Middle Eastern, and some Asian countries. The aim of this study was to document the demographic features of children with lentil allergy and to determine the role of specific IgE (sIgE) in predicting the risk of clinical reactivity and disease persistence. Methods Thirty children were enrolled. The diagnosis of lentil allergy was based on convincing history of symptoms or anaphylaxis after the ingestion of lentils, with positive skin tests and/or sIgE to lentils. To determine the diagnosis and prognosis of lentil allergy, 24 children were evaluated with food challenges. Results The median age at the onset of symptoms was 1.5yr (0.92.3) (inter-quartile range). The most frequent symptoms were immediate cutaneous (97%) and respiratory (30%) reactions, whereas eight patients (27%) reported anaphylactic reactions. The median level of lentil sIgE at the time of diagnosis was 3kU/l (1.29.6). Of the 24 challenges, 12 were positive. Fifteen patients (50%) outgrew the lentil allergy by the age of 3.5 (2.511) years. Children with an initial lentil sIgE<4.9kU/l had a significantly higher likelihood (68.4% vs. 18.2%) of outgrowing the lentil allergy than children with an initial lentil sIgE4.9 k/l (p=0.008). Conclusions Our results suggest that sIgE levels may be important for predicting clinical reactivity and persistence of lentil allergy.