Abstract Background Stress may negatively affect surgeons' performance during surgical procedures, jeopardizing patient safety. For measuring stress, complex methods are used that cannot record stress real time. This study reports stress measurements in surgeons and residents using a novel patch sensor to identify activities and risk factors of stress. Methods In this explorative study, surgeons and residents wore the HealthPatch™ during all daily activities for 2–3 days. The patch recorded heart rate variability (HRV), and real time stress percentage using a validated algorithm of heart rate (HR) and HRV. The patch was compared with self perceived stress reporting using STAI. Results A significant increase in HRV and stress percentage was shown in twenty surgeons and residents during surgery in comparison with other activities. Consultants showed lower stress levels while operating compared to fellows and residents. Stress according to the patch did not correlate with STAI outcome. Conclusions Continuous stress monitoring using a wearable sensor patch reveals relevant data on actual stress of surgeons and residents. Stress was highest performing an operation, particularly in fellows and residents.