Charles Ardai's writing has appeared in mystery magazines such as Ellery Queen's Mystery Magazine and Alfred Hitchcock's Mystery Magazine, gaming magazines such as Computer Gaming World and Electronic Games, and anthologies such as Best Mysteries of the Year and The Year's Best Horror Stories. Ardai has also edited numerous short story collections such as The Return of the Black Widowers, Great Tales of Madness and the Macabre, and Futurecrime.

His first novel, Little Girl Lost, was published in 2004 and was nominated for both the Edgar Allan Poe Award by the Mystery Writers of America and the Shamus Award by the Private Eye Writers of America; his second, Songs of Innocence, was called "an instant classic" by The Washington Post, selected as one of the best books of the year by Publishers Weekly, and won the Shamus Award.

Both books were written under the alias Richard Aleas and were optioned for the movies by Universal Pictures. Ardai previously received a Shamus nomination for the short story "Nobody Wins" and he received the Edgar Award in 2007 for the short story "The Home Front". In 2015, he received the Ellery Queen Award for his work on Hard Case Crime. Ardai's third novel, Fifty-to-One, was published in November 2008. It was the fiftieth book in the Hard Case Crime series and the first to be published under Ardai's real name.

In 2010, he began working as a writer and producer on the SyFy television series Haven, inspired by the Hard Case Crime novel The Colorado Kid by Stephen King. The first episode of Haven aired on July 9, 2010 and the last aired on December 17, 2015. In 2016, he wrote a novel based on the Shane Black movie The Nice Guys. In addition to his writing and publishing activities, Ardai serves as a managing director of the D. E. Shaw group.