The Covid-19 pandemic has affected the capital market in many countries including Indonesia. The announcement of the first Covid-19 case in Indonesia affected the share prices of companies in various sectors including the telecommunications sector. This study aims to analyze the differences in stock prices of companies in the telecommunications sector in the periods of 185 days before and after the announcement of the first Covid-19 case in Indonesia. The result of the tests conducted show that the announcement caused the cumulative average share price to differ between 10 months (185 trading days) before and after the announcement of the first Covid-19 case in Indonesia, where the average cumulative share price before the announcement was 2,596.66 and after was 1,910.43. It can be concluded that the first case of the Covid-19 in Indonesia resulted in a decrease in the average share price of telecommunications companies due to the market sentiment’s negative response to the first Covid-19 case in Indonesia.