The clinical diagnosis of allergies needs appropriate tools for the measurement of histamine release from leukocyte suspension of affected patients. In the last few years the established fluorometric procedure has been challenged by alternatives like histamine radioimmunoassays (RIA). Although measurements of histamine with the latter methods make this procedure more accessible as a diagnostic tool, further simplifications are always welcomed. A newly developed immunoenzymoassay for histamine is described in the present work and compared to a recent radioimmunoassay. Sensitivity and specificity are shown to be comparable in both procedures.