This study was designed to establish IgE values in different allergic diseases in an Israeli population and healthy controls. The geometric mean IgE in the control group was 41 IU/mL (range = 15 to 111 IU/mL) and in the atopic group 142 IU/mL (range = 36 to 556 IU/mL). The highest values were found in patients with asthma plus allergic rhinitis plus atopic dermatitis and asthma plus atopic dermatitis. The lowest values were from patients with urticaria. There was a gradual increase in IgE levels from 4 to 10 years and then a gradual decrease. IgE was significantly higher in males, particularly in the 21 to 40-year age group and above 60 years. There was no difference in IgE levels in the various ethnic groups. There was a correlation between IgE levels and the number of positive skin tests. Peripheral eosinophilia was found in one-third of the patients with low IgE and in 2/3 of the patients with IgE above 500 IU/mL. An IgE of 120 IU/mL or more was found in 56% of patients with asthma in addition to other atopic diseases. Only 10% of normal controls had an IgE value of 120 IU/mL or more. These results are similar to those reported from European and North American countries.