The rupiah was flat ahead of the decision. The currency has benefited this week from Indonesia's new cabinet that many hope would push through major reforms to boost investment and growth.
OCBC, in a note, said Bank Indonesia may supplement the rate cut with soft rhetoric, and, if so, would "serve as reminders that the Asian macro outlook remains weighed down, even if it may not be dislocating lower."
The US-China trade war and political uncertainty elsewhere has dented global economic growth, and has seen central banks adopt more policy-easing measures.
Trade-reliant economies in Asia have been especially impacted. Economic growth in South Korea slowed more than expected in the third quarter, though exports - the most important driver - showed some signs of recovery.
The won was among the best performing currencies on Thursday, advancing 0.1%.
The country's central bank has left the door open to further policy easing.
"Looser fiscal and monetary policy should help the economy to regain some momentum in the quarters ahead," Capital Economics said in a note.
Taiwan's dollar also strengthened.
For the overall region, "it seems likely that the worst of the export slowdown is behind us, providing marginal support to Asia FX if the data improves into next year," BofA Merrill Lynch Global Research said in a note.
The Indian rupee, the Singapore dollar and Chinese yuan were flat.
The Malaysian ringgit gained 0.1%. The government is working to resolve a spat with India that has resulted in calls to boycott Malaysian palm oil, a key export product.
On Wednesday, both Malaysia and Singapore said consumer prices in September rose more slowly than expected. The Philippines peso weakened 0.2% to 51.080 a dollar.