And to tease viewers, a 30-second preview was aired during the US Super Bowl event, offering glimpses of red lights in the sky and sinister scientific experiments.
A mysterious figure in a hazmat suit, wielding a flamethrower, could also be seen, with the returning gang of boys dressed in Ghostbusters costumes and fleeing on bikes.
Also shown is what appears to be a gigantic, spider-like monster, which is first pictured in a sketch then shown dominating the horizon.
The principal cast all return for the second season.
Nine new episodes have been confirmed, with titles including Madmax and The Boy Who Came Back To Life.
The Duffer brothers, who created the hit sci-fi horror show, have said that the second season takes place a year on from the first.
It is said to be inspired partly by Indiana Jones. However, the trailer suggests there will also be plenty of science fiction action.