During the rehearsals for the film, David Tennant was offered the role of the Tenth Doctor in Doctor Who (2005). This casting was not announced to the public until April 16, 2005, two weeks after the broadcast, but his fellow castmembers, and crew, became aware of the speculation surrounding Tennant. In the live broadcast, Jason Flemyng changed Quatermass' first line to Tennant's character Dr. Gordon Briscoe from "Good to have you back, Gordon" to "Good to have you back, Doctor" as a deliberate reference.
This production was originally broadcast only three weeks before the death of John Mills, who had played Professor Bernard Quatermass in the ITV serial Quatermass (1979), on April 23, 2005 at the age of 97. His death left Jason Flemyng as the only one of the seven actors to have played the character who is still alive.
On two occasions near the middle of the live broadcast on April 2, 2005, a large on-screen graphic was overlaid, advising viewers that a major news story, the death of Pope John Paul II, was being covered on BBC News 24.
This was the first live television drama to be broadcast by the BBC since Japanese Style (1983) on March 13, 1983. The next was A for Andromeda (2006) on March 27, 2006.
The production was a live broadcast to mirror The Quatermass Experiment (1953). Whereas the original series would often overrun, this production, which was given a two hour slot, finished in under one hour and forty minutes.