A UK charity says anti-Semitic attacks rose after the Israel/Gaza offensive
Nearly 100 legislators from 35 countries have gathered in London to develop strategies to combat the "growing threat of anti-Semitism".
The inaugural conference of the Inter-parliamentary Coalition for Combating Antisemitism (ICCA) is being co-hosted by the Foreign Office.
The politicians will work with experts to devise ways to fight anti-Semitism.
It comes after the number of attacks on UK Jews rose sharply following the Israeli offensive in Gaza in December.
The two-day summit is being held in the Houses of Parliament and at Lancaster House.
The attendees include a dozen government ministers, members of the US Congress and several UK ministers, including Foreign Office Minister Lord Malloch Brown.
They will share knowledge, experiences and best practice, and meet international experts from academia, law enforcement, information technology and security.
They hope to create an action plan to tackle what they have identified as the escalating global threat of anti-Semitism.
This includes physical attacks, such as that on the Jewish community centre during the Mumbai terror attacks in November, and race hatred and Holocaust denial distributed via the internet and other media.
Foreign Secretary David Miliband said: "Anti-Semitism has been with us for millennia, but has mutated in form and expression through the ages. Today it has adapted to new technologies and has no defined borders.
"The internet age, with its manifold benefits, has the downside that hate is able to travel faster and further than ever before. Modern and innovative solutions are essential if we are to combat this. So is international co-operation."
The newly-formed ICCA is an umbrella framework which assembles parliamentarians from around the world who take an active interest and involvement in confronting anti-Semitism.
It was co-founded by Labour MP John Mann, who chairs the UK's parliamentary committee against anti-Semitism.
Last week the Community Security Trust, a charity working to protect Jews in the UK, said more than 250 anti-Semitic incidents were recorded in four weeks following Israel's military operation in Gaza.
They include property vandalism, verbal threats and some physical attacks, most of which centred on north London.
The same period last year saw just 27 incidents, according to the trust.