The article focuses on several phenomena observed in the world economy in recent years that have important implications for the discussions on costs and advantages of inflation and disinflation. They include possible threats arising from disinflation, low inflation persisting in some countries at the simultaneous low level of unemployment, and the Asian crisis. New interesting directions of research were also described. Subsequently, the author presents theoretical controversies around the issue of disinflation costs. He proves that recently approaches of major schools towards short-term interrelations between production, unemployment and inflation have become closer, which is in contrast to the long-term Philips curve. However, on theoretical grounds, it is difficult to explain disinflation costs, in particular with an assumption of rational expectations. Therefore, the author presents L. Ball´s findings, which suggest that the explanation becomes more convincing when elements of the new classical economy (the role of accountability) and the new Keynesian economy (different timing of pay agreements) are taken into account. This, in turn, requires also presentation of other analyses that aim to justify disinflation costs on the macroeconomic level with economic entities´ behaviour. From the point of view of the Polish reality, presented directions of theoretical discussions on disinflation costs under existing low inflation seem to be of a particular importance.