Blue Peter was first aired on 16th October 1958. It had been commissioned to John Hunter Blair by the head of children's programmes, Owen Reed who wanted a programme aimed at children aged five to eight. The first two presenters were Christopher Trace, an actor and Leila Williams, winner of Miss Great Britain in 1957.

The initial format involved the two presenters demonstrating different activities, with Trace concentrating on traditional "boys' toys" such as model aeroplanes and trains, and Williams concentrating on dolls and traditional female tasks, such as cookery. Occasionally, Tony Hart, an artist who later designed the logo, joined the programme to tell stories. It was broadcast once a week on Monday, for fifteen minutes.

Over the years, the programme changed to reflect the times. The running time extended to 25 minutes, and at one point was shown three times a week on BBC One. The 4000th edition was broadcast on 14 March 2005. Most episodes are still broadcast live, although during the 1990s and early 2000s, when a third edition of the show was broadcast, the third programme was pre-recorded.

Almost every episode from 1964 onwards still exists in the BBC archives. This is extremely unusual for programmes of that era, and stands as testament to Baxter's foresight and initiative, as she personally ensured that recordings were kept of the episodes.

Many items from Blue Peter's history have passed into television legend, especially moments when things have gone wrong, such as the much-repeated clip of Lulu the elephant (from a 1969 edition) who defecated on the studio floor, trod on presenter John Noakes' foot and then proceeded to attempt an exit, dragging her keeper along the ground behind her.

Other well-remembered and much repeated items include the Girl Guides' campfire that got out of hand on the 1970 Christmas edition, John Noakes' report on the cleaning of Nelson's Column, and Simon Groom referring to a previous item on door-knockers with the words 'What a beautiful pair of knockers', which has usually been explained as an accidental turn of phrase, but which Groom later admitted was a deliberate joke.

Additionally, Groom is remembered for inappropriately reciting, while wearing a suit of armour, 'Once a king always a king, but once a (k)night is enough', while Peter Duncan's cookery instructions to 'finely chop one raw egg', Yvette Fielding's disastrous attempt to cook a pancake and Mark Curry driving a mini sit-on traction engine into part of the set will also go in the annals.

There have also been times when the show has broadcast breaking news in the days before 24-hour news channels. Possibly the most famous is showing the first colour images on British television of the sinking of the RMS Queen Elizabeth in 1972.

Blue Peter's content is very wide-ranging. Most programmes are broadcast live, but usually include at least one filmed report. There will also often be a demonstration of an activity in the studio, and/or a music or dance performance.

The programme is made at BBC Television Centre, and often came from Studio 1, which is the second largest TV studio in Britain and amongst the largest in Europe. This enabled Blue Peter to include large-scale demonstrations and performances within the live programme. The show is also famous for its "makes", which are demonstrations of how to construct a useful object or prepare food. These have given rise to the oft-used phrase "Here's one I made earlier", as presenters bring out a perfect and completed version of the object they are making. Time is also often given over to reading letters and showing pictures sent in by viewers.

The signature tune, in recognition of the origin of the title, is a sea shanty called "Barnacle Bill", and the programme's motif is a stylised sailing ship designed by Tony Hart. Hart's original design was never successfully used in a totally uniform fashion, with several different reproductions used in studio, on badges, the Blue Peter books and on-screen graphics.

This was until the show's redesign in 1999, when the ship's rigging and hull detail was removed, and in 2000, the flags were subtly reshaped. This version is still in use today, and now appears across all media (although the revised badges retain the old-style flags).