Leukotrienes are a recently discovered group of arachidonic acid‐derived lipid mediators. Using radioimmunoassay and high pressure liquid chromatography (HPLC), we have identified the SRS‐A sulphidopeptide leukotrienes (LTC4, LTD4and LTE4) in nasal washings from patients with allergic rhinitis who underwent nasal challenge with specific allergen. Smaller, but significant, amounts of LTB4were also detected. The concentrations of nasal leukotrienes were directly related to the dose of allergen, and were recovered in washings in a time‐dependent fashion after challenge. When the patients were subjected to methacholine nasal challenge on a control day, we found only negligible amounts of either the sulphidopeptide leukotrienes or LTB4. These findings support the view that LTC4, LTD4and LTE4might contribute to the pathogenesis of allergic rhinitis as a result of their recognized effects on mucous hypersecretion and vasopermeability, and that the potent chemoattractant LTB4might be involved in the subsequent infiltration of inflammatory