The company posted an image on its Facebook page that was taken from an original render of the Stick Canyon level from Nights into Dreams.
The image was posted without further comment, leaving it unknown what exactly Sega is planning for the series.
Given Sega's trend of bringing back its classic titles as HD ports, it is possible the teaser is hinting at a downloadable remake of Nights Into Dreams for XBLA, PSN, handhelds or iOS devices. It could also indicate a new Nights title or a track for the upcoming Sonic & All-Stars Racing Transformed.
The last game in the series was Nights: Journey of Dreams, which released for the Nintendo Wii in 2007.
Nights into Dreams originally released for the Sega Saturn in 1996. It received a remake on PlayStation 2 in 2008 which was only released in Japan.
Watch a video of Nights into Dreams below: