The Organisation for Economic Co-operation and Development (OECD) says growth and recovery are expected in 2010 in just about all world regions.
For its 30 member countries, rich nations including the US and UK, it has more than doubled its growth forecast to 1.9% for next year, from 0.7%.
But the OECD warns developed nations not to expect a smooth ride.
It said growth was being "held back by still substantial headwinds" and would be "modest" for some time.
The very measures that are helping richer nations to recover pose risks to that recovery, the OECD says.
The UK, for example, needed to come up with a concrete plan to ease concerns about the stability of the public finances, it added.
The OECD said the effectiveness of the UK's asset purchase programme - the so-called quantitative easing programme - was uncertain.
The main danger for rich countries is unemployment, according to the OECD's economic outlook. In the US, people are expected to continue to lose their jobs at a faster rate than new ones are created until sometime in the first part of next year.
For the European Union, the picture is even worse. Unemployment may continue to rise in that region until 2011.
A very different economic outlook is forecast for key emerging nations. China can expect to grow by 10%, India by more than 7%.
The other two stand-out nations are Brazil and Russia. The OECD expects Brazil's economy to rebound and expand by almost 5% after stagnating this year.
Russia is also predicted to see that kind of economic improvement next year. But its turnaround will be even more dramatic. This year, it has experienced one of the worst economic slumps in the world - contracting by almost 9%.
But those four so-called Bric countries are not part of the 30-strong OECD club.
The one member nation whose economy should perform vigorously in 2010 is also an eastern one: South Korea should rebound to grow by 4.5% in both 2010 and 2011, after ending this year with almost no growth.