The episode had an audience of 5.0 million viewers and a share of 24.5% of the whole TV audience.
Hide was the third most viewed programme of the day, with the first being the second episode of ITV's Britain's Got Talent, which earned 9.6 million viewers and a share of 43.9% of the overall viewing audience, and the second being the BBC's own talent show, The Voice UK, which had a viewing figure of 7.92m (in a later slot of 8.20pm) and a 34% share of the overall viewing audience.
While the figure is the lowest of the series so far, it is worth noting that Hide clashed with Britain's Got Talent for half an hour of the run-time. Next week's episode, Journey to the Centre of the TARDIS, will only clash with BGT for fifteen minutes.
The final viewing figures will be released next week, so expect an increase of at least two million on the overnight figure.
[Source: Doctor Who Online]