The Training Day writer is working on the screenplay, which will update the original 1929 novel by Armitage Trail into a contemporary setting.
"This is a fantasy for me, I can still remember when I saw the film at 13 and it blew my mind," Ayer told Deadline.
"I sought it out; I went after it hard. I see it as the story of the American dream, with a character whose moral compass points in a different direction. That puts it right in my wheelhouse.
"I studied both the original Ben Hecht-Howard Hawks movie and the DePalma-Pacino version and found some universal themes. I'm still under the hood figuring out the wiring that will translate, but both films had a specificity of place, there was unapologetic violence, and a main character who socially scared the s**t out of people, but who had his own moral code. Each was faithful to the underworld of its time.
"There are enough opportunities in the real world today that provide an opportunity to do this right. If it was just an attempt to remake the 1983 film, that would never work."
Scarface has previously been adapted into two films - Howard Hawks's 1932 version and the best-known 1983 Brian De Palma movie, which starred Al Pacino.
Ayer's most recent project is the upcoming End of Watch, which he has written and directed.
Watch the trailer for Al Pacino's Scarface below: