St John's Wood Synagogue chazan Moshe Haschel will retire for health reasons after Shavuot.
Mr Haschel, who has served the congregation for 19 years, will be returning to Israel. He needs a kidney transplant and is on the waiting list for a donor in both the UK and Israel.
Over the past two years, he and his wife have split their time between London and Israel, where their four children and seven grandchildren live.
He likened this to "aliyah in instalments". He said: "It was a compromise, living in Israel but coming to St John's Wood every two weeks. I am very sorry to leave the community because I made a lot of friendships and very much enjoyed my work there. It wasn't an easy decision."
Shul chair Charles Lossos said: "Unfortunately, being unwell has played a major part in deciding that the time is right for our chazan to move back to Israel."
The Haschels had "played an enormous part in community life and we will miss them".