The third episode of series three, Gridlock, pushes Doctor Who into the record books as the science fiction series with the most number of episodes.
As you might expect, Star Trek was the previous contender, with a total of 727 episodes of all of the various Star Trek series combined.
Although Doctor Who is the longest-running science fiction series, Stargate SG1 entered the record book last year as the longest consecutive running science fiction televtion show, as it ran without a break for nearly ten years. Although Doctor Who has cearly been around for much longer, and has move episodes, it has had breaks.
Doctor Who’s newly won record wouldn’t last long if the Star Trek franchise was revised, of course, sine the standard US season is twice as long as that of the UK’s.