Over 100 members of the Travelling community attended the removal of Mr Thomas Harty who was shot dead in Co Laois on Sunday morning.
A large force of gardai were on duty in Limerick including armed detectives. There were also checkpoints on all the main roads to the city and vehicles were searched.
Father Joseph O'Keeffe received the remains which went the short distance from Cross's funeral home in Gerald Griffin Street to St John's Cathedral.
Gardai reported no incidents and the funeral takes place to Mount St Oliver cemetery today after 10 a.m. Mass.
Mr Harty (26), father of four, was killed when two men burst into his caravan where he was sleeping on a halting site on the outskirts of Portarlington.
He was charged with the murder of Danny Harty, a first cousin, arising out of an incident in Limerick on March 29th, 1998.
He was due to go on trial on October 5th next in the Central Criminal Court.
A native of Limerick, he lived on a halting site on the Ballysimon Road, before moving to Portarlington.
His cousin, Danny Harty, died following a row in which slash hooks were used outside a pub.