The ongoing pandemic of Covid-19 caused by the SARS-CoV-2 virus has infected more than 6 million all over the world and has caused more than 3.8 lakh fatalities till date(1) Health workers are the frontline responders and are exposed to a plethora of health hazards. Recently, an advisory by the Indian Council of Medical Research for the use of hydroxychloroquine as post-exposure prophylaxis was hailed as an outstanding initiative for the protection of healthcare workers and high risk contacts of patients. But the evidence of effectiveness available is only from in vitro studies and non-randomised control trials of insufficient sample size. Several ongoing large scale clinical trials are focused on the same research questions, the preliminary results of which are still awaited. The present study discusses the ethics of the introduction of therapeutic or preventive interventions based on limited available evidence during the ongoing pandemic of Covid-19.