The former goalkeeper, who played 86 times for his country, told magazine Gala that he would advise homosexual players to not come out.
The 44-year-old said that homosexuality was still a taboo topic among in the German football league.
He told the magazine. “It may sound sad, but I wouldn’t advise him [a gay player] to not come out.”
Kahn added that homosexuality was no longer a “big deal” in society but said it would be “naive” to think that it was the same in professional sport.
He said that a player who did come out would have to deal with opposition fans every Saturday in the stadium. “The atmosphere is heated. There are rivalries, which can lead people to do nasty things. On top of that, how will it go down with sponsors? What will it mean for your career? The situation is more difficult than it appears at first glance.”
His comments add to an ongoing debate in Germany about why no footballers have come out.
In July the German Football Association (DFB) told gay players to come out – but quietly. A pamphlet from the DFB advised gay players to wait until the end of the season.
Chancellor Angela Merkel has also got involved in the debate, telling gay footballers in September 2012 that they should “have nothing to fear”.
German striker Mario Gomez has also said homosexual players should not be afraid to declare their sexuality but his former teammate at Bayern Munich Philipp Lahm has advised against it, stating they would be “exposed to abusive elements”.