The European Commission said the extent of corruption in Europe has been in an alarming state, describing it to be breathtaking.
The commission estimated that the corruption cost the EU economy about 120bn euros (£99bn) annually, reported BBC.
EU Home Affairs Commissioner Cecilia Malmstroem will present a full report on the problem at 11:30 GMT.
Writing in Sweden's Goeteborgs-Posten daily, she said corruption was eroding trust in democracy and draining resources from the legal economy.
For the report the Commission studied corruption in all 28 EU member states.
"The extent of the problem in Europe is breathtaking, although Sweden is among the countries with the least problems," Malmstroem wrote.
The Commission says it is the first time it has produced such a report. It also makes recommendations on how to tackle corruption.
National governments, rather than EU institutions, are chiefly responsible for fighting corruption in the EU.
The EU has an anti-fraud agency, Olaf, which focuses on fraud and corruption affecting the EU budget, but it has limited resources. In 2011 its budget was just 23.5m euros.
Malmstroem said public procurement procedures were vulnerable to fraud in some countries, while in others party financing was the main problem, or municipal bodies were badly affected. She also noted that patients have to pay bribes in order to get adequate medical care in some countries.
The EU study includes two major opinion polls, which indicated that three-quarters of EU citizens consider corruption to be widespread in their country.
Four out of 10 of the businesses surveyed described corruption as an obstacle to doing business in Europe.
In Sweden, 18% of people surveyed said they knew someone who had received a bribe, compared with a European average of 12%, Ms Malmstroem said.
Despite that finding, she said Sweden "is undoubtedly one of the countries with the least problems with corruption, and other EU countries should learn from Sweden's solutions for dealing with the problem," pointing to the role of laws on transparency and openness.
Organised crime groups have sophisticated networks across Europe and the EU police agency Europol says there are at least 3,000 of them.
Bulgaria, Romania and Italy are particular hotspots for organised crime gangs in the EU, but white-collar crimes like bribery and VAT (sales tax) fraud plague many EU countries.
Last year, Europol Director Rob Wainwright said VAT fraud in the carbon credits market had cost the EU about 5bn euros.