This was the last Doctor Who serial until 1983 to be advertised with a Radio Times front cover. It featured Jon Pertwee photographed with talk show host Michael Parkinson, singer and actor Paul Jones and his son, Matthew. The magazine also featured an interview with Parkinson and Matthew Jones about why they liked the series.
Producer Barry Letts was not completely happy with Alan Bromly's work on this serial. He felt Bromly shot some scenes too simply and hadn't moved with the times, instead using techniques that belonged in 1950s live television. Letts had wanted to direct this serial himself but he was busy with Moonbase 3 (1973).
Fans voted this number 52 in a countdown of the 163 Doctor Who (1963) stories in Outpost Gallifrey's 40th anniversary poll in 2003, making it the most popular of the four serials to feature the Sontarans.
Beginning with this story, individual episodes are listed as Part One, Two etc. This replaced the previous system of calling them Episode One, Two and so forth, established in 1966 with The Savages. The naming structure introduced in this serial would be used through to Survival in 1989, with the single exception of Destiny of the Daleks.