Eleven young men from Waterford were amongst the 145 Irish men who answered the call to defend the Spanish Republic in 1936.
Wreaths will be laid at the memorial adjacant to the Bishop’s Palace Museum at 5.00pm by relatives of the men.
Seamus Ryan is one of the organisers.
He says Waterford is unique in the number of men that went to fight in defence of the Spanish Republic.
Each year the family, relatives and friends gather on May day to remember those men and the sacrifices that they made.
One of them, Mossie Quinlan, paid the ultimate sacrifice and was killed in battle.