Andrzej Supron, who won silver in the Greco-Roman lightweight division at the 1980 Moscow Olympics, says he is "surprised and outraged by the suggestion to remove this ancient sport from the games."
He says he is sending the medal back to IOC President Jacques Rogge.
Supron is also a former world and European champion.
Last month, seven-time world champion Valentin Yordanov of Bulgaria returned his gold medal from the 1996 Atlanta Olympics.
Wrestling is now competing with seven proposed new sports for a spot on the 2020 program. The final decision will be made by the IOC in September.