Postoperative nausea and vomiting is one of the most distressing and frequent complications associated with anesthesia and surgery. In this case, we present complete cardiac block attacks developing after retching and vomiting without nausea in early postoperative period. Within close follow-up and monitoring period, two acute cardiac block and asystole attacks developed in postoperative fifth and sixth hours. The patient also had a syncope attack. In the first attack the patient recovered completely following immediate intervention and without intervention in the second attack. No pathologic finding showing the reason of the attacks was apparent in the detailed laboratory and clinic investigations. After the second attack 4 mg ondansatron HCl was administered intravenously. After an uneventful period, the patient was transferred to the clinic in the second postoperative day. It was concluded that postoperative retching and vomiting seen in this patient may develop as a result of sudden cardiac effects developing from vagal stimulations in the upper gastrointestinal tract as well as a result of various perioperative factors.