The artist and creator passed away in a hospital in the Philippines on Friday morning (May 11), reports Flip Geeks.
DeZuniga suffered complications following a stroke in April brought about by a bought of pneumonia.
He was best known for his work on Conan and as the co-creator of DC Comics characters Jonah Hex and Black Orchid.
The artist was the first Filipino to work for DC and Marvel Comics.
"RIP Mr Tony DeZuniga," said fellow Filipino artist Leinil Yu on Twitter. "Thanks for the inspiring art and presence."
Fans and comics creators had banded together to help raise money for DeZuniga's mounting hospital bills, selling sketches and t-shirts during Free Comic Book Day last weekend.
DeZuniga is survived by his wife Tina.