More than 100 knives were handed in to police in just one day at a Cardiff police station.
The haul, which includes a samurai sword and even a machete, was given to police in Ely last week during a recent amnesty.
The scheme comes amid a sharp rise in knife crime in the past decade.
Latest figures from the Ministry of Justice show that there were 1,309 crimes involving a knife or sharp instrument across forces in Wales and England in the year ending September 2018.
It is an increase of 38% compared to September 2009 when there were 950 offences recorded.
The shocking impact of knife crime
Superintendent Wendy Gunney said: "Knife crime has risen across the country, and we are not an exception to that.
"The threat of knife crime in some of our communities is very real, and this is where we are focusing our efforts to reduce harm.
"For every individual involved in an incident there are family members and friends who will themselves be devastated."
Over the past few years, knives have been used in a number of serious attacks in the city.
In 2016, Matalan workers Zoe Morgan, 21, and Lee Simmons, 33, were stabbed to death outside their workplace in Queen Street.
Jealous ex-boyfriend Andrew Patrick Saunders , who murdered the couple, was given a life sentence with a minimum 23 year term.
That killing came just a few months after Llanedeyrn man Lynford Brewster was found with stab wounds on a footpath.
Last week, Dwayne Edgar, Robert Lainsbury and Jake Whelan were convicted of the murder following a retrial at Bristol Crown Court . The trio are set to be sentenced next week.
And last year, 18-year-old Aaron Bingham was jailed for the murder of father-of-two Sean Kelly in a vicious and unprovoked attack .
Nicholas Saleh, 46, was also found guilty of manslaughter following killing in Adamstown.
South Wales Police insisted that while knife crime was "rare" in south Wales, it was not being complacent.
It launched Operation Spectre last summer - which saw 101 people arrested and scores of knives seized.
Officers have also launched a public campaign in across communities and on social media under the banner of "Lives Not Knives".
Superintendent Wendy Gunney said: "We need to be constantly determined to push back individuals and groups that use weapons to support their criminality, especially where the most vulnerable are put at risk as a result.
"We want to encourage everyone to let their local police and community support officers know if they have suspicions that someone is carrying a knife, or alternatively call Crimestoppers anonymously with any information you can share.
She added: "Carrying a knife increases the chances of you or a loved one getting hurt, as it makes the chances of a situation escalating out of control that much more likely."
