This article briefly reviews the advances in our understanding of asthma with a particular focus on the role of inflammation, before providing a concise overview of current knowledge of leukotrienes in the pathophysiology of the disease. The development of leukotriene receptor antagonists and synthesis inhibitors in briefly described; and acute exercise, allergen, and aspirin challenge studies with these agents are reviewed. Clinical studies with leukotriene antagonists and inhibitors have confirmed the central role of leukotrienes in asthma pathophysiology. In conclusion, we suggest that the new generation of leukotriene receptor antagonists may be suitable as first-line therapy in patients with mild to moderate asthma. Further studies are required to determine whether the leukotriene synthesis inhibitors will be equally effective or provide any additional antiinflammatory benefit.