SummaryTotal circulating IgE levels were measured in a carefully selected normal population, using a highly sensitive double antibody assay. The mean level of 36.3 u/ml found in this group is much lower than that reported in all previous studies. No circadian rhythm was evident, but IgE levels varied slightly from day‐to‐day. IgE levels in 100 serum samples were compared using the double antibody assay and the Phadebas lest kit. based on a solid phase technique. A poor correlation was obtained with values below 100 u/ml, however, there was an excellent correlation for samples with IgE levels above this fig