Sulphasalazine is a specific inhibitor of nuclear factor kappa B (NF-kappa B) which plays a key role in asthma. To determine the impact of sulphasalazine in. the treatment of chronic asthma, BALB/c mice were sensitized and challenged with ovalbumin. Mice With experimentally induced asthma in group I received saline, group II sulphasalazine 200 mg/kg, group III sulphasalazine 300 mg/kg, and group IV dexamethasone 1 mg/kg intraperitoneally once a day in the last 7 days of the challenge period. Histological findings of the airways were evaluated by light and electron microscopies. Dexamethasone and sulphasalazine in both doses significantly improved all airway histopathologic parameters of asthma except numbers of goblet cells. Both doses of sulphasalazine improved thicknesses of basement membrane better than dexamethasone. Dexamethasone reduced the number of mast cells better than sulphasalazine (200 mg/kg). Further studies are needed to evaluate the efficacy of sulphasalazine in the treatment of asthma.