BACKGROUND: Salmeterol, a new beta2-adrenergic receptor agonist is a long-acting bronchodilator and benefits patients -with asthma who have nocturnal symptoms. We wished to assess the efficacy of inhaled salmeterol (50 microgram bid) compared to inhaled salbutamol (200 microgram qid) for the treatment of bronchial asthma, particular. ly nocturnal asthma. METHOD: We randomly assigned 35 patents (25 female and 0 male patients, 15 to 50 years old) to one of two treatment groups one group received 50 microgram of salmeterol twice daily and another did 200 microgram salbutamol four times per day. And this study was performed as an open-label and the 6 weeks inhalation period. RESULTS: Analysis of symptom scare; Day and night time symptom score showed significant difference between salmeterol and salbutamol Group (p<0.05). Number of days for additional bronchodilator requirements The number of days and puffs for additional bronchodilator were lower in the salbutamol group in either day and night time (p<0.05). Pulmonary function test; FEV1 showed significant increase in salbutamol group compared to salbutamol group after 2 and 4 weeks inhalation period. Adverse effects, We found no evidence of tolerance to the bronchodilating effects of salmeterol, and adverse reactions to all the treatments were infrequent and mild. CONCLUSION: For the management of bronchial asthma, salmeterol given twice daily is superior to salbutamol given four times daily.