Financial institutions are exposed to different risks which should be systematically controlled to avoid a negative influence on their financial standing. One of risk measures is value-at-risk. VaR allows for identification of risk sources and in turn methods to limit risk exposure. By definition it is a statistical risk measure which denotes a maximum loss to the portfolio with a specified probability. In economic terms it specifies an amount which can be lost in a specified period. Apart from theoretical background of VaR, we show in the paper an empirical example for the Polish banking industry. In the empirical research we explore if mergers and acquisitions in the Polish banking sector lead to lower risk exposure from an invest...