Executive summary Prior research shows that accounting conservatism exists in mature economies. However there is not too much research about accounting conservatism in transitional economies. This paper analyses the influence of institutional and political factors on accounting conservatism in Eastern European countries which have already joined the European Union. I researched the levels of unconditional and conditional conservatism in Eastern Europe and compared them with Western European results. I did not find evidence that there is conditional conservatism in Eastern Europe. My research shows that there was conditional conservatism only in Poland during the analyzed period. I found significant evidence proving my expectations regarding the influence of the quality of law, securities law and the risk of expropriation on conditional conservatism.