While the Covid-19 epidemic, which affected the whole world, caused difficult days in terms of health, it also affected the economic and social life quite a lot. As part of the measures taken to prevent the spread of the epidemic, many workplaces had to take a break from their activities. It has become mandatory to take certain health measures for workplaces that have to continue their activities and have started to operate again within the scope of the normalization proces. Many measures have been taken, especially the application of mask, distance and cleaning rules in daily life in the workplace. Vaccination of employees has also taken its place in the legal world as a precaution. With the massive application of the vaccine in our country as of January 2021, it has brought along discussions whether the vaccine can be made compulsory in the workplace and whether the employment contracts of those who do not have the vaccine can be terminated for just cause or valid reason. Again, it has been a matter of debate whether not wearing a mask in the workplace will be a just cause and/or a valid reason.