NUI Galway Student's Union is now mandated to support the legalisation of cannabis.
Students at the university were asked, as part of the annual union elections, to vote on the question of legalising the drug.
The question put to the student body in yesterday's poll was: "That NUI Galway Student's Union actively supports the legalisation and regulation of the cultivation, sale and possession of cannabis for adults age 18 and over."
Votes were counted today, and the union is now obliged to support the issue, after the question passed by 1,796 yes votes to 838 - a ratio of more than two to one.
MEP Luke Flanagan, a well-known advocate of legalisation, attended an information night late last month.
The issue was put on the ballot by the request of 500 union members, forcing the union to put it to the membership at large.
NUIG Student's Union could not immediately be reached for comment.