Lithgow starred in the recent fourth season as the Trinity Killer but was murdered by Dexter (Michael C. Hall) in the finale.
However, Lithgow refused to give too much away when he was asked if he will be appearing on the show again.
"You know, people who work on Dexter never answer questions like that," he told E! Online. "There's a cultural secrecy surrounding Dexter. It makes it a lot of fun. Half the time, we didn't even know what was coming."
Lithgow also revealed that he loved playing Arthur Mitchell and joked: "I did for bathtubs what Janet Leigh did for showers back in the '50s."
Lithgow recently won an Emmy in the 'Outstanding Guest Actor In A Drama Series' category for his role in Dexter.