The COVID-19 outbreak that emerged in China in December 2019 and influence whole World, took its place among the major epidemic diseases that occurred in the historical process. The main measure taken to prevent the spread of the disease is the social isolation. The main purpose of this research is to determine the healthy nutrition practices of the people in the COVID-19 quarantine process. Within this context, 982 people, who were residing in Istanbul in which more than 60% of COVID-19 cases found in Turkey have been included in this study, and these people were under self-isolation. Research data were collected between March 15th and April 1st, in which COVID-19 cases reached its peak inTurkey. As a result of factor analysis, nutritional information, emotion about healthy nutrition, healthy and unhealthy nutrition dimensions were created. As a result of the research, it was determined that the quarantine process affected the healthy eating behaviors of the participants in positive way, and that the participants have been eating more healthy manner. Healthy eating behavior is more common in the elderly people than in the young people. Having nutritional information showed a positive effecton healthy eating behaviour. In this process, the participants started to consume the foods they have not been consumed before, and to produce the foods they have not been produced.