The subject of this paper is inflation in Poland in the first decade after the Second World War and its goals include identification of causes, examples, phases and consequences of inflation in People’s Poland in that period. In socialist economy inflation was only in small part expressed by increase in prices and in large part in different examples of “bad” market (shortages, queues, rationing etc.). Therefore the analysis concentrtes on inflation understood as consumer surplus demand. Subsequent parts of the text analyse: theories on inflation sources and mechanisms in socialist economies and inflation in Poland between 1945–1949 and from 1950–1955. Our research showed that consumer surplus demand was almost permanent which allowed to consider inflation (although not in open form) a permanent feature of socialist economy in Poland. The results of research also confirmed the hypothesis on surplus investments in industry as fundamen‑ tal and cyclically returning cause of inflation that existed also in the so called pro‑consumption phases of economic policy. During limited investment expansion periods inflation was limited through severe and consequently executed deflation measures (such as in 1948 and 1949). During conversion to market production similar effect was achieved by blocking wage increase (1954–1955). Sporadic use and ineffectiveness of anti ‑inflation policy instruments was caused primarily by limits set by political and doctrinal principles.