Scottish Rugby is changing its rules from 1 February to ban transgender women from competing in contact versions of the women’s game.
The SRU has said “contact rugby for players in the women’s category is limited to those whose sex was recorded as female at birth”.
Scottish Rugby estimates the playing population of trans people in Scotland to be fewer than 10.
The move follows earlier decisions by the English, Irish and Welsh unions.
The new policy takes into account guidance from World Rugby and the UK-wide Sports Councils’ Equality Group.
Transgender women could previously participate in contact versions of the women’s game in Scotland depending on the outcome of a “thorough medical process including testosterone tests” prior to registration to play.
Scottish Rugby said: “We acknowledge that this is an evolving space, and we will continue to review all available information as it emerges.”
Transgender men may continue to play contact rugby in the men’s category provided a risk assessment has been undertaken by their club and the outcome logged with the SRU.
A statement on the Scottish Rugby website said: “We all have a responsibility to look after the participants in our game, with their wellbeing and safety at the centre of everything we do.
“We fully acknowledge this is a difficult and sadly divisive societal issue, and that has been especially apparent over the last few months. Scottish Rugby has been mindful of this and aimed to deal with the issue in a sensitive manner.
“Scottish Rugby wishes to be as inclusive as possible and is only imposing such eligibility restrictions based on the guidance provided. The decision to amend our eligibility criteria was not taken lightly as we seek to address conflicting viewpoints.
“Our gender participation policy recognises the need to balance considerations of safety and fairness with our underlying desire to be as inclusive as possible.
“At this moment in time, Scottish Rugby has opted to make a decision which puts safety first, based on the current research.”