Background: The COVID-19 pandemic continues to rise. In order to control the COVID-19 pandemic, healthcare professionals have been subjected to increased exposure to work stress. In this systematic review, we aimed at investigating the prevalence and determinants of immediate and long-term post-traumatic stress disorder (PTSD) effects on healthcare professionals by the COVID-19 (SARS CoV-2) and SARS-2003 (SARS CoV-1) pandemics. Methods: This systematic review was conducted according to the recommendations of the Protocols for Systemic Review and Meta-Analysis (PRISMA) statement. Only studies reporting the prevalence of PTSD (frequency, percentage) and related risk factors (adjusted odds ratio (OR)) in healthcare professionals (HCPs) during the SARS CoV-2 and SARS CoV-1 pandemics were included. The following databases were screened: Medline, Embase, PsychINFO, and Health Psychosocial Instrument (HaPI). Results: Six of eight studies reported PTSD symptoms among healthcare professionals during the COVID-19 pandemic in China (three), Singapore (one), India (one), and the United States of America (USA) (two), while two studies reported symptoms during the SARS-2003 pandemic in China (one) and Singapore (one). Sample sizes ranged from 263 to 5062 with a combined total of 10,074 participants. All of the studies self-reported the level of exposure to coronaviruses (CoV-1 and CoV-2) and severity of PTSD. Seven studies reported the prevalence of immediate PTSD and determinants, while one study reported delayed-onset PTSD (3 years after CoV-1 pandemic). Determinants of immediate PTSD were reported for the CoV-2 pandemic, while those for long-term PTSD were reported for the CoV-1 pandemic. Conclusions: A comprehensive understanding of the prevalence and determinants of immediate or long-term pandemic PTSD for healthcare workers can improve prevention, diagnosis, and management. Rigorous research measuring the prevalence of PTSD and its associated risk factors (adjusted OR) for the CoV-2 pandemic are envisaged. Although strategies to resolve immediate PTSD are key, long-term PTSD must not be overlooked.