Denmark, with a score of 91, is perceived as the least corrupt country in the EU, while Greece is seen as the most corrupt.
The Berlin-based NGO, Transparency International (TI), published its 2013 corruption perceptions index, covering 177 countries.
The ranking is based on expert opinion of public sector corruption on a scale from 0 (highly corrupt) to 100 (very clean). Seven of the 28 EU member states scored below 50.
Many non-European countries scored in the same league as EU member states. New Zealand shares the top spot with Denmark.
Germany slipped a point from last year and scored 78, but is still ranked in the top 12.
Bosnia and Herzegovina and Serbia scored 42 and are now tied for 72nd place. Croatia is in 57th position, with a score of 48, whilst Montenegro and Macedonia are tied for 67th place and with a score of 44.
The worst performers are Afghanistan, North Korea and Somalia, on just eight points each.