Bank Indonesia (BI) cut the 7-day reverse repurchase rate by 25 basis points to 5.50%, as expected by only two of 19 economists in a Reuters poll. The other 17 had predicted no change.
Governor Perry Warjiyo said the decision was consistent with Indonesia's low inflation outlook.
BI's two other policy rates for overnight deposit and lending facilities were trimmed by 25 bps to 4.75% and 6.25%, respectively.
Last month's rate cut was the first time since September 2017, and many saw as the start of an easing cycle.