David Grimason has been calling for tighter controls since his two-year-old son Alistair was killed during a gunfight at a Turkish cafe in 2003.
Mr Grimason will be at the UN in New York, attending the final negotiations for an international arms trade treaty.
He said a strong treaty was the biggest tribute he could give to Alistair.
The family were holidaying in the seaside village of Foca when their son was killed on 7 July 2003.
The youngster was asleep in his pram when an argument broke out at a nearby table and a man opened fire.
On the ninth anniversary of his son's death, Mr Grimason said: "It's always a difficult day for me.
"Every year since Alistair was killed I've visited his grave in East Kilbride.
"But this year I've taken the decision to be at the United Nations negotiations. It's the best tribute I can give to Alistair I suppose, to try and effect change and to stop these tragedies happening to other families.
"I was a father back in 2003, just enjoying life. When Alistair was killed, it destroyed his life, my family's life - it's a very difficult life to lead, being the victims of gun violence."
Mr Grimason said said he had been involved with the Control Arms campaign, run by Amnesty International, IANSA and Oxfam International, since 2004.
He told BBC Radio Scotland: "I do feel something can be achieved. We in Scotland don't have to live with firearms on a daily basis but unfortunately it is a global problem.
"My son was killed in Turkey, where there's a high number of civilians carrying handguns.
"But it's not an isolated problem in Turkey either. It's a global problem, it's worldwide, and this international treaty would prevent the transfer of weapons between nations if there's evidence they're going to be used in violation of international law.
"Hopefully an effective treaty would reduce the flow of weapons throughout the world, over time."
First Minister Alex Salmond met with Mr Grimason before he left Scotland, and said the Scottish government was strongly supportive of an international arms trade treaty.
"David Grimason is to be praised for his work drawing this vital issue to the attention of both the public and the international community," he said.
"His own son was killed in a tragic incident in Turkey yet he has had the courage to speak out to stop others being affected in the same way."
Jamie Livingstone, Oxfam Scotland's campaigns manager, said the charity was "humbled by David's decision".
He added: "It can't have been an easy decision to come to New York at this time, but David is playing a key role in pushing for the sort of legally-binding rules which will save lives."
First Minister Alex Salmond has praised the work of Scottish campaigner David Grimason who is in New York attending the United Nations Arms Trade Treaty Conference.
Today (Saturday) is the anniversary of the death of Alistair Grimason, David's infant son who was tragically shot and killed in Turkey in 2003.

The Swede said valuable personal items and all of his clothing were taken, but added that the Claret Jug, awarded to the winner of The Open, had already been returned to the R&A on Monday.
"I am extremely grateful my family were not in the house," said Stenson, 41.
"I am going to try not to let this spoil the week in any way."
Merseyside Police are investigating a burglary in Formby, less than seven miles from Royal Birkdale.
Police believe the incident occurred between midday and 14:25 BST and cash, cards, electrical items, clothes and watches were stolen.
An R&A spokesperson said: "We were very sorry to hear about the burglary and have offered any assistance we can provide to Henrik and his family."
Stenson teed off at 09:47 BST on Thursday and finished on one under par.
He was a late starter as Friday's second round got under way.
A father whose toddler son was shot dead in a cafe in Turkey will mark the anniversary of his death by campaigning for global action against firearms.
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Defending Open champion Henrik Stenson's rental home was burgled as he played his first round at Royal Birkdale on Thursday.