Neostigmine is a cholinesterase inhibitor and a primary agent for pharmacologic antagonism for reversal of nondepolarizing muscle relaxants. Due to the parasympathomimetic action, neostigmine can cause nausea, bradycardia, and bronchial constriction. Here we present a patient who developed bronchospasm following bradycardia with loss of consciousness, after the administration of one small dose of neostigmine and atropine. This is the first case to demonstrate such a complicated response to neostigmine. Literature findings suggest neostigmine may induce relatively rare but severe adverse effects during anesthesia emergence, and the newly developed neuromuscular blockade antagonist-sugammadex may be a better choice.