Retirement systems are extremely complex social, economic, legal, and organisational structures. The authors of retirement systems are faced with a great number of dilemmas. The pension related expenditure has systematically been increasing in the developed world, also as a percentage of GDP, due to the fast ageing of societies both as a result of the fact that life expectancy has become longer and due to a decline in the number of children per family. Consequently, according to the estimates of the International Monetary Fund, in order to maintain the liquidity of public retirement systems in industrialised countries in the light of between 1995 and 2050 it would be necessary to increase expenditure for this purpose on average by 1.8% of GDP annually. It is also a great challenge to Poland, which introduced its new retirement system in 1999. This paper analyses the possible impact of the new pension system on Poland's economic development. It discuses pension funds in the new architecture of the Polish retirement system and lists conditions for such an impact. It also analyses position of the pension funds on the Polish financial market and discusses opportunities for using open pension fund investment potential. Eventually it focuses on development opportunities for Polish economy in reference the pension system.