A statement issued by delegates meeting in Brighton read: "The conference believes that ending the occupation demands concerted and sustained pressure upon Israel including an economic, cultural, academic and sporting boycott".
In addition, delegates called on the British government to press for an arms embargo against Israel.
Speaking to Ynet, the union's secretary, Mary Maguire, said the call was symbolic and carried little practical consequences.
"We support the State of Israel and will continue our good relations with professional Israeli unions. But the aim of our call is to end Israel's occupation," Maguire said.
The union also called on Israel to retreat to the borders before the Mideast war of 1967, to allow Palestinian refugees to return to a future Palestinian state and to dismantle its settlements in the Golan Heights.
Delegates also condemned an economic boycott imposed on the Palestinian Authority last year when Hamas won the general elections.
Hagit Klaiman contributed to this report