Medical professionals work in a constantly stressful environment. The nature of the profession requires routine extended working hours, but little is known about the effect of long working hours on selective physiological measures. A cross-sectional feasibility study was conducted from 1 October 2017 until 30 April 2018 on medical doctors in a tertiary health centre in northwest Malaysia. There was a total of 55 study participants recruited. The overall systolic blood pressure (SBP) was highest after working 24-hour stretch (p=0.006) and the overall diastolic blood pressure (DBP) were highest after working for 33 hours in a single stretch, at the end of on call rotation (p