The report by CapGemini and Royal Bank of Canada is the latest of several recent surveys highlighting the strong rise in the region's wealthy while also hinting at persistent inequality.
The survey found that the number of Asian millionaires grew 9.4 per cent in 2012 to 3.68 million people, up from 3.37 million the year before, and their combined wealth rose 12.2 per cent to USD 12 trillion.
Economic growth, strong stock markets, rising property prices and the region's high savings rates helped boost fortunes.
The report defines wealthy as those with at least USD 1 million in liquid assets. It covered 10 Asian countries and territories including China, Japan, Australia and South Korea.
Asia was surpassed only by North America, where the millionaire population grew 11.5 per cent to 3.73 million with combined wealth rising 9.8 per cent to USD 12.7 trillion.
Asia's millionaire population outnumbered Europe's for the first time in 2009, and in 2011 it edged out North America for top spot, according to previous editions of the report. The report's authors forecast that Asia would reclaim its crown as soon as 2014.
The superrich, defined as those worth at least USD 30 million, grew even faster than the millionaire population at large. Their ranks in Asia grew 15.4 per cent last year to 25,000 while combined wealth rose 18 per cent, about double the global average.
Earlier this month, the Hurun Report, which tracks China's wealthy, said surging stock prices helped mint 64 new billionaires this year, raising the total number to 315, compared with none a decade ago. At about the same time, Wealth-X, which follows the world's wealthy, said Asia's superrich population grew 4 per cent to 44,505.
Eric Lascelles, RBC asset management's chief economist, chalked up some of the rebound in the fortunes of the superrich to more aggressive investments, which tend to get hit harder in downturns and rise more rapidly on the rebound.
"Equally we need to acknowledge that globalisation over the past few decades has increased inequality to some extent," he said. "We have seen rates of poverty decline quite nicely over that period as well but that's not to say that wealth or incomes have risen as quickly in the lower end as it has in the higher end."