A new method of collection of nasal secretion, by dilution with condensed mositure of the exhaled air, is described. This method may be defined as a sefl-administered nasal lavage. The method permits quantitative determination of pH, relative viscosity, and electrolyte and protein composition. Concentrations of sodium, potassium, calcium, total protein, IgA, IgG, IgM, secretory compoenent and polysaccharide are reported for normal subjects. Significant correlations were noted between the relative viscosity and variables: dry weight, total protein and calcium.