Olea europaea (olive) pollen extract was prepared by aqueous extraction and characterized by biochemical and immunochemical methods. Two components, displaying respective mol. wt. of 17,000 and 19,000, were the most reactive allergens, being the doublet (designated Ole e I) recognized by most sera tested. The 19,000 mol. wt. component, purified by conventional biochemical procedure and lectin-affinity chromatography from the Ole e I doublet, was deglycosylated and analyzed by SDS-PAGE and by ELISA inhibition. The results obtained suggest that the 19,000 mol. wt. component represents the glycosylated form of the 17,000 component.