Introduction: Secretory phospholipases A2 (sPLA2) are increased in bronchoalveolar lavage fluid of patients with asthma or acute respiratory distress syndrome. Intratracheal sPLA2 instillation induces acute lung injury in animals. We hypothesized that sPLA2 would stimulate mucus secretion in vitro and that intratracheal sPLA2 exposure would induce mucus hypersecretion and airway inflammation in the ferret trachea in vivo. Methods and results: In vitro, porcine pancreatic sPLA2 at a concentration of 0.5 or 5 units/mL significantly increased mucous glycoprotein (MG) secretion from the excised ferret trachea. P-bromophenacylbromide (p-BPB, a sPLA2 inhibitor), quercetin (a lipoxygenase inhibitor), or MK886 (a 5 lipoxygenase inhibitor) each at 10^-4 M significantly reduced sPLA2 induced MG secretion. Secretory PLA2 stimulated MG secretion was decreased in Ca²⁺ free medium. In vivo, ferrets were intubated for 30 minutes once daily for 3 days using an endotracheal tube coated with 20 units of porcine pancreatic sPLA2 mixed in water-soluble jelly. Constitutive MG secretion increased 1 day after sPLA2 exposure and returned to control 5 days later. Human neutrophil elastase (HNE) at 10^-8 M increased MG secretion in the sPLA2 exposed trachea compared to that in the control trachea, but methacholine (MCh) at 10^-7 M did not. Secretory PLA2 induced secretory hyperresponsiveness continued for at least 5 days after sPLA2 exposure ended. Conclusion: Secretory PLA2 increased tracheal inflammation, MG secretion, and secretory hyperresponsiveness probably through enzymatic action rather than by activation of its receptor.