In 1999, he learned he had a brain tumour. He had several operations in the following year and his condition appeared to have stabilised. Cardinal O'Connor, in his personal funeral plan, had requested that Frank Patterson sing Ave Maria at his funeral. Patterson was diagnosed with a recurrence of his illness on 7 May 2000 and he cancelled his appearance at the cardinal's funeral on the following morning, 8 May. Following the cardinals's funeral, Patterson briefly recuperated and resumed performing. Patterson's last performance was on 4 June 2000 at Regis College in Weston, Massachusetts, a suburb of Boston. Shortly thereafter he was admitted to the Memorial Sloan-Kettering Cancer Center where he lapsed into a coma and died at the age of 61."It was said the whole world seemed still while he sang", in The Irish Times, 17 June 2000.
