EN
The main aim of the article is to present the phenomenon of deflation and its connection with depression. The detailed aim is the answer to the question to what extent the current economic crisis causes threats of deflation in Poland. This study consists of four main parts. In the first, the phenomenon of deflation is presented - its definition, types and costs. In the second, the connection between deflation and depression is outlined - its theoretical and empirical aspects. In the third part, an index of deflation vulnerability is presented - methodology and evaluation for 35 countries (data comes from a survey by M.S. Kumar et al.). In the last part, a risk of deflation is evaluated for Poland in the period from 2000 to 2008, especially in the context of the current economic crisis.