The increase in the consumer price index was compared to a 1.6 percent gain in July. It was the slowest growth pace since April when consumer prices rose 1.5 percent.
Stable consumer prices last month helped the Bank of Korea cut interest rates by 25 basis points to 2.25 percent -- the lowest since November 2010.
The cut followed warnings of recession from Finance Minister Choi Kyung-Hwan who expressed concern about a long period of low growth and sluggish domestic demand.
The central bank has set a band of 2.5-3.5 percent as its inflation target for this year.