Abstract Cardiac arrest in operation theater is rare and the most successful CPR because mostly patient is already intubated. In this case report, we describe the successful management of a 26-year-old male with a chronic perforated peptic ulcer who led to cardiac arrest during surgery and subsequently developed a pneumothorax. The patient was admitted to the Iranian hospital of Dubai and transferred to the operating room as an emergency case. Anesthesia was induced with 100 μg fentanyl, 2 mg midazolam, and 70 mg ketamine. Keywords: cardiac arrest, pneumothorax, resuscitation, CPR in OR.