BACKGROUND: Agricultural products have been mainly consumed food in Korea. However, there have been no published data to observe the IgE-sensitization rate, cross-reactivity and allergenic risks to home-made agricultural food in adult allergy patients. OBJECTIVE: The aim of this study was to evaluate the IgE sensitization rate and cross-reactivity to home-made agricultural products and to establish a basic data for planning treatment and prevention methods of food allergy in adult allergy patients. METHOD: Five thousand three hundred forty allergy patients complaining of various allergic diseases and visiting the Allergy Clinic of Ajou University Hospital were enrolled. Skin prick tests were performed with home-made agricultural products including soybean, corn, buckwheat, chestnut, rye grain, potato, nut, wheatflour, carrot, onion and rice. If A/H ratio for each agricultural product showed more than 2+ on skin prick test, it was considered a positive response. ELISA inhibition tests were performed for cross- reactivity to agricultural products. RESULT: The sensitization rate to home-made agricultura products ranged from 2.2% to 9.5% in adult allergy patients. Sixty-five (3.8%) and sixty-four (3.7%) out of the one thousand seven hundred sixteen patients showed positive responses (A/H> or =2+) to soybean and corn, positive responses to buckwheat and chestnut were noted in 84 (4.8%) and 66 (3.8%) patients respectively, followed by rye grain (9.5%), potato (5.7%), nut (5.4%), wheatflour (5.1%), carrot (5.1%), onion (3.3%) and rice (2.2%). Wheat flour and rye grain inhibited IgE binding to each other. Soybean, corn, Hop. J, wheatflour and rye grain extracts inhibited IgE binding to potato extracts in potato sensitized subjects sera. There was a strong inhibition between corn and soybean extract. CONCLUSION: The sensitization rate to major agricultural products ranges from 2.2% to 9.5% in adult allergy patients, and buckwheat and soybean were the most prevalent ones among the home-made agricultual products in this country. Agricultural products-specific IgE antibody that cross reacted with other agricultual products can cause allergic reaction in foods allergy.