The 30-second promo features the show's star Michael C Hall in character as Dexter.
"I'm feeling like my old self again," he says. "Renewed, recharged, refocused. With nothing to stop me from being me."
The trailer is the second promo to be released. An earlier video, which emerged last month, announced that "hell breaks loose" when the show returns.
Showtime's president David Nevins has suggested that the new episodes will focus on Dexter's relationship with his sister Deb and will see the serial killer "getting back to his roots".
Edward James Olmos, Colin Hanks, Brea Grant, Billy Brown, Mos Def and Molly Parker are among the stars who have signed up to appear in the sixth season.
Watch the new teaser trailer for Dexter season six below: