Various proteins have been detected in human nasal mucus, but their electrophoretic pattern has not been extensively investigated. Therefore, we have studied this pattern in nasal mucus samples from a group of 40 healthy subjects (20 males and 20 females). The electrophoretic separations have been performed under both native and denaturing conditions. The electrophoretic pattern of nasal mucus obtained under denaturing conditions and stained with Coomassie brilliant blue R-250, reveals 17 distinguishable areas into which protein bands are divided, with no significant variations from one individual to another. Eight of these areas contain high concentrations of nasal mucus proteins, whereas lower concentrations are seen in the other nine areas. The electrophoretic patterns of nasal mucus differs from that of eye mucus. The method used for sampling is rapid, simple, requires no local anaesthetic, and supplies an adequate quantity of proteins for laboratory testing. Electrophoresis under denaturing conditions proves to be the better of the two techniques, since it permits good separation of proteins. Among the protein bands revealed in our study there are some already known proteins (i.a. pre-albumim, albumin, lysozymne), but the presence of other proteins which have yet to be identified cannot be excluded. Hence, a study is underway for the purification and identification, by amino-acid sequencing, of the various proteins which make up each band. A through definition of the protein pattern of nasal mucus might prove useful for detecting anomalies in its composition, for example, in cases of olfactory disorders.