Aaron Singh, 20, said the rule used by the Welsh Amateur Boxing Association (WABA) prevents him from competing because of his faith.
The English amateur body, England Boxing, reversed the ban following a campaign from Sikh and Muslim boxers.
The WABA said whether or not the rule was discriminatory would be decided this month by its members and board.
It added it would also consider if the “sporting integrity” of amateur boxing would be affected by abandoning the rule.
Mr Singh, who is from the East Midlands but is studying philosophy and economics at Cardiff University, said: “For me to compete, they’re asking me to shave all of my beard off, which is against my religion.
“I spoke to the WABA on the phone and they told me that it was a health issue.
“To have someone tell me that I’m not allowed to participate in something like a sporting event because I’ve got a beard – I personally see that as being wrong.
The Sikh principle of Kesh prevents the removal of any hair on the body, because it is considered sacred and a gift from God.
Amerpreet Singh, a prominent figure within the Sikh community in Cardiff, agrees with Mr Singh and said: “To me, it’s 100% discriminatory. By saying you cannot fight in Wales as an amateur boxer because you have a beard is heartbreaking.
“Sikhs fought in the first and the second world war. When we fought in those wars, they didn’t fight with a trimmed beard. They fought with their turbans and their full beards.
Amateur boxing is governed internationally by the International Boxing Association (AIBA), under which boxers continue to be prevented from competing with facial hair.
But AIBA was stripped of its Olympic status in May, meaning the International Olympic Committee will set its own regulations for boxing in next year’s Tokyo Olympics.
Prof Carwyn Jones is a lecturer in sports ethics at Cardiff Metropolitan University. He said he understood the WABA’s reasoning for the rule, but does not feel it justifies the current ban.