Afridi achieved the record mark during Pakistan-West Indies opening Twenty20 International here on Saturday (July 27). He scored two sixes in the match, which Pakistan won by two wickets.
The 33-year-old all-rounder has scored 314 sixes in 359 ODIs, 52 sixes from 27 Tests and 34 hits over the fence in 61 Twenty20 Internationals.
Afridi made his international debut in 1996 against Kenya in a ODI. He holds the record for the fastest century in ODIs, scoring a ton in just 37 balls.
Recently, he set another record by becoming the first ODI player to complete 7,000 runs and 350 wickets.
The next best on the highest sixes list is West Indies' Chris Gayle with 353.