The article explores key micro- and macroeconomic factors with an impact on credit risk and analyzes the credit risk model prevalent in Poland’s banking sector. Credit risk is one of the most important risks in the banking sector, the author says. He adds that risk management should be subject to strict owner control and regulatory and supervisory measures. On the basis of quarterly data for a period from the first quarter of 1997 to the second quarter of 2013, Wdowiński estimated an error correction model for aggregate credit risk in Poland, as measured by the proportion of non‑performing loans (NPLs) in total loans. The key macroeconomic factors considered by the author were GDP, the interest rate, the unemployment rate, and the exchange rate. An ex post simulation for the 2008–2012 period, based on an adverse macroeconomic scenario for Poland, showed that such a scenario could lead to a marked increase in credit risk for non‑financial enterprises and households, Wdowiński says. As a result of this scenario, the banking sector could be affected by a significant decline in activity and its financial position would deteriorate. This would mean fewer investment opportunities for banks and a decline in their capital position, which would reduce their ability to absorb losses. Such a situation, the author concludes, could lead to “second­‑round” effects based on limiting financing for the real economy due to increased credit risk and increased lending margins.