Young Sinn Féin supporters rejected the wishes of the party's national executive and backed a motion to boycott the powerful World Economic Forum, attended by the party's chief negotiator, Mr Martin McGuinness.
The proposal from Belfast Ógra Sinn Féin said the forum "is not a platform to promote our revolutionary struggle".
The conference also accepted a motion to send a delegation to the next World Social Forum, an "anti-globalisation" alternative to the economic forum.
Mr McGuinness attended the forum's annual meeting in Davos, Switzerland, in January, and took part in a panel discussion on the Northern conflict.
In supporting the motion, delegates rejected an ard chomhairle amendment that the party would "consider" boycotting the forum. It also supported a motion to recognise the social forum as "a viable alternative vision of the world in which we live".
In a debate on international affairs, the ard chomhairle's amendment was one of the few motions to provoke a count rather than a show of hands.
The only person on the ardfheis platform to vote against the executive was also the youngest, the party's European election candidate for the south region, Mr David Cullinane from Waterford. Mr McGuinness took part in the Northern discussion with the SDLP leader, Mr Mark Durkan, Mr Gregory Campbell, of the DUP, and the UPP's Mr David Ervine.
A motion to look at the feasibility of boycotting Spanish goods and holidays was dropped from the debate. The motion, from the Pól Kinsella cumann Derry, was protesting at the "Spanish government's failure to negotiate peace with the Basque people and the Spanish government's violation of human rights".
