Transparency International named the three Baltic nations among the highest gainers in its 2013 Corruption Perception Index, with Estonia leaping four places to 28th.
The annual index measures the perceived degree of corruption in 177 countries and territories, ranking them from least corrupt to most corrupt.
Latvia and Lithuania both rose five places to 49th and 43rd respectively. Russia leaped six places, but its score of 28 out of 100 did not improve, while the Baltic nations all improved their score by three to four points.
Estonia now has 68 points (64 last year), Lithuania 57 (54) and Latvia 53 (49). The institute said that scores below 50 indicate a serious corruption problem.
Besides the Baltic states, a number of southeast Asian nations, Senegal and Greece were the other notable gainers.
Denmark and New Zealand tied for first place with a score of 91, while Finland fell from first to joint third with 89 points.
Mimicking last year's results, Afghanistan, North Korea and Somalia tied for last place with eight points.