The article delves into what the author terms a deposit war in the Polish banking sector, a process that has been under way since 2008, according to Mokrogulski. The author analyzes the causes and outcomes of the process. The research is mainly quantitative and incorporates a single­‑equation econometric model. However, the analysis is also comparative in nature, Mokrogulski says, because the Polish banking sector is evaluated against its counterparts in other EU member states. The analysis is supplemented with institutional issues related to financial supervision in Poland. The author’s calculations show that the “deposit war” mostly applies to deposits with maturities ranging from one to six months. Due to interest rate rises, banks reported a significant increase in their short­‑term deposit volumes, the author says. His models show that an increase in interest on deposits by 1 percentage point led to an average growth of the deposit volume by 2.7 % on a monthly basis. In the case of deposits with original maturities of over 1M up to 3M the growth was 5.4 %, the author says. Moreover, despite higher interest costs at the time of the deposit war, the financial condition of Polish banks did not deteriorate compared with their counterparts in other countries in Europe, according to Mokrogulski. Liquidity measures introduced by the Polish Financial Supervision Authority (KNF) additionally encouraged banks to maintain liquid assets and funds at sufficiently high levels. In the future, providing long­‑term funding to banks could help prevent further deposit wars, the author concludes.