The Israeli ambassador faced an angry reception from protesters on Wednesday as he marked the appointment of Israel's first honorary consul for Wales.
Ron Prosor visited Cardiff to attend a ceremony at the Welsh Assembly, welcoming Philip Kaye to the role.
But the ambassador was later heckled as he arrived to give a lecture at Cardiff University Debating Society.
Demonstrators from the Stop the War Coalition had pledged a 100-strong protest, but police estimated that only around 60 supporters of the group, together with Green Party members and Socialist Worker activists, had turned up.
By the time Mr Prosor arrived at the university, only 20 demonstrators were left waiting for him. They screamed "murderer" and displayed pictures of dead Palestinian children as his motorcade drove past.
Palestinian students argued with Mr Prosor over last year's Gaza conflict and the economic situation in the Palestinian territories. Several walked out shouting "you are not welcome in Cardiff". In an open letter to Mr Prosor the Stop the War Coalition wrote: "You represent a racist, war-mongering, inhumane regime. "
But with one of the highest levels of security seen for years in the city, the event went ahead. Victoria Jones, president of the debating society, said the invitation was "an invaluable opportunity to bring the Israel-Palestine conflict into an educational arena".
Earlier, marking Mr Kaye's appointment, the ambassador celebrated the new role. He said: "I'm very happy that we have not just named an honorary consul, but that we are doing it first in Wales. Next will be Scotland and Northern Ireland. I hope Philip can be Israel's Prince of Wales."
Mr Kaye, 54, is a longstanding member of Cardiff's Jewish community. The MD of a toys and fireworks company, (he is a qualified pyrotechnician) he represented the UK in the 1977 Maccabiah. He said: "This is a pioneering project. and there is much to build on."