Foundation series は3部作(Trilogy)が初めに書かれ、後に、前編として2本、後編として2本が追加されました。
- Foundation prequels series:
- Prelude to Foundation. 1988. ISBN 0-553-27839-8. (occurs before Foundation)
- Forward the Foundation. 1993. ISBN 0-553-40488-1. (occurs after Prelude to Foundation and before Foundation)
- Original Foundation trilogy:
- Foundation. 1951. ISBN 0-553-29335-4.
- Foundation and Empire. 1952. ISBN 0-553-29337-0., Published with the title 'The Man Who Upset the Universe' as a 35c Ace paperback, D-125, in about 1952
- Second Foundation. 1953. ISBN 0-553-29336-2.
- Extended Foundation series:
- Foundation's Edge. 1982. ISBN 0-553-29338-9.
- Foundation and Earth. 1986. ISBN 0-553-58757-9. (last of the Foundation series)