Purpose – The aim of this paper is to conduct an empirical analysis regarding the impact of Covid19 on fifteen sectors through reviewing its effect on BIST-100 in Turkey. The analysis is conducted for the period of March 11-April 11 in 2020 in comparison with the same periods in years 2018 and 2019.Design/methodology/approach – The main methodology adopted for this paper is quantitative research; including descriptive statistics, correlations, and risk-return distributions. In depiction of the results of the analyses; graphs and tables are utilized. Findings – It is found that the risk in all sectors has increased during the first period of the Covid19 pandemic (with average of 0.205%) compared to the same period of 2019 (with average of 0.042%), and 2018 (with average of 0.021%). However, the average loss in returns of the sectors has decreased gradually. The most profitable sector during the first period of Covid-19 in Turkey is “health and pharmaceutical industry” with 9.21% return whereas the sector which has recorded the highest loss in its returns during this period is “clothing and textile sector” with -17.40% returns. In terms of riskiness, the sector which has the highest risk during the first period of the pandemic is also “health and pharmaceutical sector.” Lastly, the least risky sectors are “multi-sectoral holdings” and “metallurgical and mechanical industry.” Discussion – Firstly, we argue that the excessive increase in risk can be explained by the impact of Covid-19 pandemic. Secondly, it seems that there are especially some industries whose positive returns have helped the index not to turn into negative during the first period of the pandemic such as “health and pharmaceutical industry,” and “aviation industry.” “Aviation industry” in particular is examined in the paper due to its special situation. Thirdly, it is confirmed that “petroleum and chemical industry” is one of the locomotive industries of Turkey as it is in many emerging countries. Fourthly, people seem to attach more importance to the consumption of necessary goods than ever in order to sustain their lives in an environment of uncertainty resulting from Covid-19 pandemic.