Up the Downstair is the second studio album by Porcupine Tree, first released in May 1993. It was originally intended to be a double album set including the song “Voyage 34”, which was instead released as a single in 1992, and other material that ended up on the Staircase Infinities EP (1994).

In 2005, it was partially re-recorded, fully re-mixed, remastered and re-released along with the Staircase Infinities EP as a double album. The re-release contains a new mix by Steven Wilson, along with recorded drums by Gavin Harrison that replace the electronic drums of the original version. Steven Wilson has stated that the title of the album came from a line in the song “Voyage 34.”