The gargantuan specimen - a Wels catfish - measured 2.85 meters (or 9.4ft) in length.
Alessandro Biancardi had been fishing in the River Po in Italy's Lombardy region when he hooked what turned out to be a veritable monster.
After hauling the beast onto his boat, he and his colleagues measured it and discovered that it was a whopping 2.85 meters in length, making it one of the - if not the biggest catfish ever caught.
"When it surfaced for the first time, I really realized that I hooked a monster," Biancardi wrote.
"I was alone facing the biggest catfish I [have] ever seen in 23 years."
After it had been measured, the huge fish was released back into the river again.
You can check out footage of the catch in the video below.