This diploma thesis deals with the capital market in the Republic of Croatia with the impact of the financial and COVID-19 crisis on the operations of the Zagreb Stock Exchange. From the aspect of trading and a certain type of business of the Zagreb Stock Exchange, the capital market of the Republic of Croatia can be characterized as insufficiently developed. In addition to the Zagreb Stock Exchange, the Central Depository and Clearing Company and the Croatian Financial Services Supervisory Agency are extremely important institutions for the smooth operation and functioning of the capital market. In addition to these institutions, institutional investors are also important: investment funds, pension funds and insurance companies. Institutional investors enable the implementation of unhindered turnover and trading in securities on the capital market. Disturbances in the market, like financial and economic crises, have a great impact on the entire economy, including the capital market, as part of economic activities. This is the basis of the thesis and the impact of the financial crisis in 2008 and the COVID crisis in 2020 on the operations of the Zagreb Stock Exchange. The financial crisis in 2008 on the world markets began in 2007, while the first effects on the market of the Republic of Croatia appeared in 2008. The analytical and practical part of the paper covers the movement of market capitalization, number of transactions and stock exchange indices Market capitalization as such represents the total value of issued shares at their current prices. In addition to market capitalization, stock exchange indices are extremely important, which in the case of the Zagreb Stock Exchange are divided into stock (CROBEX) and bond (CROBIS).