Inhaled 3-carene at a concentration of 5,000 mg/m3 caused bronchoconstriction in isolated, ventilated and perfused guinea pig lungs. This effect was inhibited by the cyclooxygenase inhibitor diclofenac (100 µM) and the thromboxane/prostaglandin endoperoxide-receptor antagonist L-670,596 (1 µM). 3-Carene exposure also increased the amount of thromboxane in the perfusate from the lungs. In cultured calf pulmonary arterial endothelial cells 3-carene caused a dose-related release of arachidonic acid. Thus, the results obtained in this experimental model may have implications in the understanding of the pathophysiology of 3-carene-induced obstructive pulmonary disease in humans.