During filming Kyle Gallner suffered a panic attack whilst being tied to a cross, which the crew were unaware of at first, thinking he was still acting.
The Westboro Baptist Church planned to protest Red State at its premiere at the Sundance Film Festival. Kevin Smith in turn planned a counter protest which he and his fans took part in. At the premiere the counter-protesters heavily outweighed the handful of Westboro protesters who showed up. This occurred 12 years after Smith's first film to tackle religious controversy, Dogme (1999), drew protests from certain sects of the Catholic Church, one of which Smith jokingly took part in himself.
There is no score for this film. The entire soundtrack consists of songs sung within the film itself.
After a screening of the film in Kansas City, Kevin Smith interviewed two life long Westboro Baptist Church members (Shirley Phelps niece and son) who had defected a few years prior. They both enjoyed the film and even complimented Smith on how realistic certain aspects of religious fanaticism are depicted.
A first for writer/director Kevin Smith, he has stated this film is a strict non-comedy saying, "It's a nasty-ass $4mil horror flick with few (if any) redeeming characters."
Kevin Smith: Smith has a quick off-camera cameo at the end of the film, as a prison inmate, yelling the last line in the film.