Fentanyl, a synthetic opioid, is a popular choice amongst anesthesiologists in the operating room. Preinduction iv fentanyl bolus is associated with coughing in 28-45% of patients. Coughing due to fentanyl is not always benign and at times may be explosive requiring immediate intervention. We have studied the role of aerosol inhalation of salbutamol, beclomethasone and sodium chromoglycate in preventing fentanyl induced coughing and have compared their efficacy. Two hundred patients aged 18-60 yr, undergoing elective laparoscopic cholecystectomy were randomized into four groups of 50 each. Group I served as control, while Groups II, III and IV received an aerosol inhalation of salbutamol, beclomethasone or sodium chromoglycate 15 min prior to entering the operating room. Following iv fentanyl (2 micro g x kg(-1)) the incidence of cough was recorded and graded as mild (1-2), moderate (3-5) and severe (> 5) depending on the number of coughs observed. Results were analyzed using 'z' and Fischer's Exact test. A P value of < or = 0.05 was considered significant. The incidence of cough was 28% in the control group, 6%, 0% and 4% in the salbutamol, beclomethasone and sodium chromoglycate groups respectively. Occurrence of cough was significantly low (P < or = 0.05) in the treatment groups, however the difference amongst the groups was not significant (P >/= 0.05). The use of salbutamol, beclomethasone or sodium chromoglycate aerosol 15 min prior to iv fentanyl administration minimizes fentanyl-induced coughing.