The poll in Croatia was conducted in June on 600 people, while TI and the Gallup poll organisation conducted it on 55,000 people in 69 countries, Mesic's office said in a press release.
Political parties are viewed as potentially the most corrupt group in 45 countries.
Croatians view political parties, the judiciary and bodies of representatives as the most corrupt groups. Nearly half of those polled said there was more corruption today than three years ago, while 36 per cent said the level of corruption was the same.
On the global scale, 44 per cent of members of the public think corruption will rise in the next three years, 30 per cent said the situation would change, while 19 per cent said there would be less corruption.
Thirty-two per cent of Croatian citizens think there will be less corruption in the next three years, 38 per cent expect no changes, while 25 per cent expect the situation to deteriorate.
The global corruption barometer reflects the opinions of members of the public, whereas the corruption perception index brings experts' opinions.