MEXICO CITY—Stubbornly high inflation and increased inflation expectations prompted the Bank of Mexico to raise interest rates last month despite concerns about weakening economic growth, minutes to the meeting showed Thursday.

The board of governors voted unanimously to lift the overnight interest-rate target to 8.25% from 8% on Dec. 20, a second consecutive increase that pushed the rate to its highest level since January 2009. The central bank kept the door open for further increases and said interest rates would remain...