Rationale To understand the current condition of food allergy in Japan, we investigated the immediate type food allergy cases in the past two years in collaboration with more than 2000 doctors. Methods We sent questionnaire to contributing doctors every three months from 2001 to 2002. Contributing doctors were asked to report immediate type food allergy cases seen by those doctors by mail. The details of questionnaire consisted of age, sex, cause of food allergy, symptoms, IgE CAPRAST, and type of treatment. To only focus on the immediate type food allergy, cases were restricted to the cases, of which symptoms occurred within one hour after ingestion of suspected food. Results The total number of reported cases reached 3882 cases. Although reported cases ranged from 0 to 80 years old, 50% of reported cases (1969) were below 2 years old. The most common cause was hen's egg (38.3%), followed by cow's milk (15.9%), wheat (8%), shellfish (6.2%), fruits (6%), buckwheat (4.6%), fish (4.4%) and peanuts (2.8%). Interestingly, the cause of food allergy was completely different from childhood to adulthood. Food-induced anaphylaxis was seen in 10.9% out of reported cases. Compared to our previous investigation, fruits allergy such as kiwi and banana seemed to be increasing trend in our society. Conclusions Based on these data, countermeasures against food allergy are on going in collaboration with the Ministry of Health, Labor, and Welfare in Japan in order to improve quality of life of patients with food allergy.