The objective of the present article is to revise the biochemical and pharmacological knowledge of the leukotrienes, including the enzymatic and cellular processes that participate in its synthesis. The half-filled biological effects through diverse receptors as the cystenil-leukotrienes, have a primordial participation in the physiopathology of the asthma. The 5-lipooxigenase inhibitor, 5-lipooxygenase-activating protein antagonist, and cystenil-leukotrienes, are three classes of new modulators for clinical use. Their effect has been revised in diverse clinical models of asthma, as the one induced by allergens, exercise, aspirin and in multicenter asthma trials are reviewed. The conclusions in general guide to that their pharmacology and the clinical experience that one has, contain them as a new therapeutic role in the treatment of the asthma.