Abstract Since 2012, the European Commission has embarked on the ambitious project to harmonize public sector accounting rules on all levels of government within Europe, mainly to improve the quality as well as the comparability of financial data. Although International Public Sector Accounting Standards were deemed not to be suitable for a simple take-over because of various reasons, they nevertheless shall function as a primary reference point for developing European Public Sector Accounting Standards. A total of 21 out of 28 central governments have already reformed their accounting standards to accrual accounting, and some of them have also relied on IPSAS in this exercise. Apart from governments, various international and supranational governmental organizations have also since the end of the 2000’s been reforming their accounting system to accrual accounting, and have in the same way relied on existing IPSAS. This paper explores accounting practices found in ten intergovernmental organizations (Commonwealth Secretariat, Council of Europe, European Commission, IAEA, INTERPOL, ITER, NAPMA, OECD, International Criminal Court, WFP) whose statements are prepared in compliance with IPSAS. It analyzes how overt and covert options contained in IPSAS with relevance to the activities of intergovernmental organizations are exercised and evaluates in which areas of accounting material differences in accounting practices can be found, which may hinder the comparability of financial statements prepared on the basis of IPSAS.