Longest running Sci Fi TV series+

[DavenSac]

What is the longest running Science Fiction TV series?

[kev100]

Dont know but would guess at either Dr. Who, or The Outer Limits possibly.

Let me know if you find out Davensac.

[mycatis]

Wouldnt be Star Trek would it? (Although there was a long gap between the first sreies and the new ones, do you mean longest run without a break?)

[Aquariel]

For number of episodes it would probably be Doctor Who (713 episodes approx with more being made), and then Star Trek (703 live action eps in 5 different series to date).

If it's based on first year/last year then maybe the Twilight Zone would qualify (1959-2003).