Hong Kong's Hang Seng shed 0.3 percent to 22,484.31. Australia's S&P/ASX 200 dropped 0.9 percent to 4,930.70. Benchmarks in Singapore, Taiwan, and Indonesia fell more than 1 percent. The Philippines dropped 3.8 percent. South Korea's Kospi was marginally lower at 2,000.10.
Daniel Martin of Capital Economics in Singapore said two concerns are generally weighing on emerging market stocks.
"The first is that the Fed might soon start tapering its assets purchases. The second is that growth in Asia has generally disappointed the market this year, as the global trade recovery has faltered," he said.
One particular pocket of concern is China. A survey by HSBC showed that manufacturing in the world's No. 2 economy slipped in May, a sign the country's fragile recovery might be weakening. The official monthly figure on factory output is due Saturday.
Otherwise, the lack of major data releases for the day deprives investors of reasons to wade into stocks, analysts said.
"A lack of first tier data releases today will limit activity although the tone will likely remain relatively downbeat," said Mitul Kotecha of Credit Agricole CIB in a market commentary.
The latest speculation surrounding the Fed came after the release of positive consumer confidence and housing news on Tuesday. That led investors to fret over the prospect of the Fed reducing its bond-buying.
Japanese export stocks fell as the yen crept higher against the dollar. Honda Motor fell 3.4 percent.Yamaha Motor lost 3.6 percent.
Benchmark oil for July delivery was down 53 cents to $92.60 per barrel in electronic trading on the New York Mercantile Exchange. The contract for the benchmark grade fell $1.88 to close at $93.13 a barrel on the Nymex on Wednesday.
In currencies, the euro rose to $1.2979 from $1.2934 late Thursday in New York. The dollar fell to 100.77 yen from 101.15 yen.