COVID -19 is new disease caused by SARS-CoV-2, a novel virus that emerged at the end of 2019. It is truly remarkable how the virus spread all over the world creating a devastating effect or non-infectious, to the background . There is no medical conversation or conference without reference to it. While the optimal ways to diagnose and manage this disease are being studied with ‘feverish’ pace, controversies spring up almost daily. This has understandably put the treating physicians in a state of confusion, which is matched only by the complexity of the entire illness. We present here a Casebook of COVID – 19, where actual cases seen at different medical centers are discussed along with brief chapters on various aspects of this disease. They have been contributed by clinicians who have been at some time associated with the editors or with the PD Hinduja Hospital. We do hope this book will be of great interest to the practicing clinicians, microbiologists, hospital administrators and public health professionals.