The main part of the show was the "Brain of Britain" quiz itself, originally called "Ask Me Another".

An incorrect answer at any point ends the contestant's turn, and the question is offered to the others in a toss-up via silent buzzer.

If there is a tie for high score, the contestant with the most bonus points (for five-in-a-row and correct answers on questions missed by others) is the winner.

[2] The show also features "Beat The Brains," a segment in which two questions submitted by a listener (or, in the Grand Final, the previous series' winner) are read.

The submitter is "awarded" the consolation prize of a round of applause from the audience if both questions are answered correctly.

After his death in April 2002, the new question setter was Kevin Ashman, who has the distinction of winning both Brain of Britain and Mastermind.

For much of its life the theme music of Brain of Britain was the opening of the fourth movement of Wolfgang Amadeus Mozart's Eine Kleine Nachtmusik, but in a 'modernised' version by Waldo de los Ríos.

The theme was changed to a more conventional version in the early 1990s, a performance by the Academy of St Martin’s in the Fields conducted by Neville Marriner.