Some £83,000 was raised by the 130 volunteers who manned phones in London and Glasgow for UJIA's Super Sunday.
The theme of the event was the charity's promotion of Jewish identity in difficult times.
Among many young volunteers was north Londoner Danielle Fox, 25, who was keen to give something back after going to Israel for the first time in summer on a UJIA Birthright tour.
"I wasn't someone who grew up in a particularly Jewish environment but UJIA Birthright completely changed that for me," she said. "Going to Israel made me feel like I was in touch with my identity in a way I hadn't been before."
Ruth Grace ran the UJIA Glasgow telethon, which raised £7,400 towards the overall total.
"I think people take for granted that we'll always have a Jewish community and that young people will want to stay involved when they're older," she observed. "But we can't rely on that.
"We need to give them experiences which inspire them and a reason to keep up their Jewish identity."
Proceeds from the fundraisers will go towards the charity's core programme.
u_9vbi5zmpgrp0XIBg2JeTEAd7XtwjoQ2LRgssSt3r8=.html