The U.S. Food and Drug Administration announced in May it would uphold the 1983 ban, The Harrisburg (Pa.) Patriot-News said Thursday.
Critics of the ban say the policy is discriminatory and that all donors are screened for the AIDS virus and other infectious diseases.
The newspaper said the American Red Cross and blood banks have urged the FDA to revise its rules, which require that male donors be asked if they have had sex with another man at any time since 1977.
Gay activists say the policy discriminates against gay men, while small blood banks are frustrated by a chronic need for more donors.
Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania, said the policy is based on fear and prejudice.
"It just doesn't square up with the science and it's not asking the right question," he told the newspaper.
He said he thinks the right question would ask about "risky behavior," like unprotected male-to-male sex or drug use.