This story aired in the following countries. They are listed in chronological order according to known airdate. If no month is noted, the actual airdate is not confirmed, and is a close approximate. (Refer also to Selling Doctor Who for expanded airdates.)
- New Zealand may have been sent the prints that had been used by the ABC in Australia. The serial was not screened due to censorship issues.
- In the Spanish dub, the Animus speaks with a male voice, whereas in the original English, it was female.
- In the Spanish edition of part six, the "Next Episode" is given by voice-over as "EL LION" to match the caption - and yet The Crusade did not screen in any Spanish-language countries.
- The film of part six that the BBC retained until 1984 had a different "Next Episode" caption that read "THE SPACE MUSEUM". It was thought that this change was done because The Crusade was deliberately withheld from sale to Muslim countries, due to the story's content and subject matter. But since only nine serials from A to L were dubbed into Arabic, and The Crusade was not sold outside the Commonwealth, the caption must have been changed for other reasons...
- The BBC was still offering Inside the Spaceship, The Web Planet, The Space Museum, The Time Meddler and Galaxy 4 for sale as late as 1974. We therefore think that the BBC amended the caption at that point, to reflect that The Space Museum was now the next serial after The Web Planet in terms of the package that was available. (On that basis, the "Next Episode" captions for the last installments of the other serials would also have been amended accordingly... All we need to do is find one to be sure! (The BBC does hold a version of Inside the Spaceship without the cliffhanger link to Marco Polo; it's not clear when this edit was made - it's possible it was done in 1974 as noted above, or not until the mid-1980s, along with similar edits to other stories when the reissued package of 17 William Hartnell stories was released for syndication to the United States.)
- A complete print of part six with the original caption was recovered from Nigeria in the mid-1980s; a TV station in Nigeria had bought the serial in 1966, but a different broadcaster in the same country aired the serial in 1973.
- The serial was reissued by the BBC in late 1985, and sold to: