The service said 86% of new HIV infections were in gay men
The blood transfusion service has rejected calls from gay men's groups to lift the ban on them donating blood.
It has told the Scottish Parliament petitions committee HIV is rising in gay men and donor selection is the only way to keep blood products safe.
The Scottish National Blood Transfusion Service said it was not discriminating just recognising behavioural risks.
But campaigners said heterosexuals posed just as much a risk if their behaviour was unsafe.
The petition was submitted to the parliament by Rob McDowall, supported by a number of gay and lesbian groups.
It argues that France, Italy and Spain have all lifted a blanket ban on gay men giving blood.
The Blood Transfusion Service's UK-wide policy currently prohibits men who have had sex with another man from being a blood donor.
The service said 86% of all new HIV infections occurring last year in Scotland were in gay men.
Although all blood donations are tested, some early stage infections are not always picked up.
The transfusion service also said the figures showed that some gay men were continuing to give blood despite being asked not to do so.