We report a case of drug-induced myoclonus possibly related to palonosetron, a second-generation 5-hydroxytryptamine-3 receptor antagonist which was administered as a prophylaxis for postoperative nausea and vomiting in a 28-year-old female. The recurrent episodes of myoclonus jerk involving the head, neck and shoulder persisted for a period of 4 days. The patient also exhibited an episode of severe bradycardia leading to hypotension 7 h after surgery. To our knowledge, this is the first report presenting these adverse events potentially associated with the use of palonosetron.