In Jan. 1976 ten Protestant workmen were shot dead at Kingsmills, with two others surviving the merciless attack.
The service was held in Bessbrook Town Hall, with friends and relatives of those killed stepping forward to lay a wreath at the memorial.
Danny Kennedy, an Ulster Unionist assembly member testified the courage and dignity of all those that had lost their loved ones, in a moving tribute.
Kennedy explained that even though the event had happened three decades ago, that the event remained embedded in the memories of all those that had gathered together.
He stated, “Despite the profound and enduring sadness of the families involved, they have always avoided lapsing into bitterness or sectarianism, and have borne their grief and loss with great dignity.”
The Service was organised by the Kingsmills Memorial Committee, with the Archdeacon of Armagh, Raymond Hoey giving the address.Bea Wharton, whose son Kenneth was among the victims, said it was important the anniversary of the murders was remembered.
Jane Lemmon, whose husband Joseph was murdered in the attack, said the victims' relatives would never forget what happened, reported the BBC.
DUP MP Jeffrey Donaldson and Willie Frazer, of the victims' group FAIR, also attended the service.
