We report of a successfully treated case of fatal bronchospasm, which developed after N-acetylcysteine bolus intratracheal instillation in a 49-year-old female patient with bronchial asthma undergoing laparoscopic cholecystectomy. N-acetylcysteine has been widely used as a potent mucolytic agent since 1963, with few reported adverse reactions. Its mucolytic action is due to the breakage of disulfide bonds in mucus mucoproteins. Most adverse reactions to N-acetylcysteine are usually mild and respond to the termination of the medication and symptomatic treatment with antihistamine. However, several cases of fatal bronchospasm have been reported in asthmatic patients after inhaled or intravenous N-acetylcysteine. N-acetylcysteine induced bronchospasm could be avoided in most asthmatic patients if its concentration is not allowed to exceed 10%, and concomitant β₂-selective bronchodilators are utilized. Nevertheless, asthma is still a potent risk factor and requires special precautions, including careful risk-versus-benefit assessment, close observation and the immediate availability of resuscitation equipment and staff in the event of life-threatening bronchospasm.