As there is no specified drug available to fight COVID-19, it is essential to have a different strategy to fight this virus. In the present study, using molecular docking, we have identified possible protease inhibitors of COVID-19 by the molecules present in Nigella sativa L. (black cumin), which is a reputed healing herb extensively used for processing Ayurvedic and Unani remedies. Herein, we perform molecular docking and study of various physical properties/descriptors of four derivatives of thymoquinone found in the essential oil of the said seeds and they are compared with the docking results of chloroquine to determine its potential against COVID-19 infection.