Grass allergy is the most common pollinosis in Northern Italy. Some patients with grass allergy show polysensitization against other pollens and plant-derived foods. In these patients oral allergic syndrome (OAS) is frequently associated. To evaluate the correlation between food allergy or food sensitization and specific IgE against panallergens such as Bet v 1 and Bet v 2, we studied 56 children (mean age: 8 years 5 months) suffering from respiratory allergy due to grass pollens were enrolled. Specific IgE against the most important food, inhalant allergen and Bet v 1, Bet v 2 were performed by ImmunoCAP technology (UniCAP 1000, Pharmacia Diagnostics, Uppsala, Sweden). We found 14 children (25%) sensitized to Bet v 1 and 13 (23%) to Bet v 2; in 24 cases (42.3%) a sensitization to at least one of the 2 panallergens was observed. Five of the 14 cases (36%) sensitized to Bet v 1 showed food allergy and 8 (57%) food sensitization; 6 (46%) of the 13 children sensitized to Bet v 2 showed food allergy and 7 (54%) food sensitization; only one case of Bet v 1 specific IgE without food allergy or sensitization was seen. Sixteen subjects (29%) showed food allergy (group A); 20 children (35.5%) multiple sensitizations to inhalant and at least one plant-derived food (group B); 20 subjects (35.5%) only inhalant allergens (group C). Sensitization to Bet v 1 (P<0.03) and Bet v 2 (P<0.009) is from a statistical point of view significantly higher in groups A and B than in group C. In the 16 patients with food allergy hazelnut was the major triggering food (50%), followed by peanut (38%), kiwi (31%), apple and walnut (19%). Specific IgE for Bet v 1 is more associated with nuts and legumes, while Bet v 2 is more related to fresh fruit and vegetables. In conclusion grass pollinosis is frequently associated with polysensitization to other pollen and food allergens. Bet v 1 and Bet v 2 specific IgE are significantly higher in these patients than in patients with grass monosensitization, and this sensitization may be considered a possible risk factors to evolve later into food allergy. Among the offending foods, legumes and the nut group are mostly related to Bet v 1, while vegetables and fresh fruits to Bet v 2.