Comedian Tony Hancock starred in the show, playing an exaggerated and much poorer version of his own character and lifestyle, Anthony Aloysius St John Hancock, a down-at-heel comedian living at the dilapidated 23 Railway Cuttings in East Cheam.
The series was influential in the development of the situation comedy, with its move away from radio variety towards a focus on character development.
The radio version was produced by Dennis Main Wilson for most of its run. After Main Wilson departed for his television career, his role was taken by Tom Ronald. The television series was produced by Duncan Wood. The distinctive tuba-based theme tune was composed by Angela Morley, then known by her original name, Wally Stott.
The radio series broke with the variety tradition which was then dominant in British radio comedy, highlighting a new genre: the sitcom or situation comedy. Instead of the traditional variety mix of sketches, guest stars and musical interludes, the show's humour derived from characters and situations developed in a half-hour storyline. This then relatively novel format, of what was in effect a single sketch each week lasting the entire half-hour (though in the radio version James and the others sometimes played different roles), was reflected in the show's title, which aptly described the series as Hancock's "half-hour".
Roger Wilmut, in his 1978 biography of Tony Hancock as a performer, credits two British radio comedy shows, already running in 1954, with establishing an uninterrupted 30-minute sitcom format: A Life of Bliss, written by Godfrey Harrison and starring George Cole, and Life with the Lyons, a programme heavily based on the US tradition of sitcoms; he therefore dismisses the notion that Galton and Simpson invented the genre.
The comedy gradually shifted to observation, with a less strong emphasis on a narrative. The playlet "Look Back in Hunger" (spoofing John Osborne's Look Back in Anger) in the episode "The East Cheam Drama Festival" from the fifth series, showed that writers Galton and Simpson were in touch with developments in the British theatre, in the use of sighs and silent pauses, something Osborne's style had in common with the plays of Harold Pinter, whose work began to emerge towards the end of the series' run. In addition, the measured pacing of the episodes was unusual in an era of fast-talking radio comedians, such as Ted Ray, who typically used a machine-gun style of delivery to fill every single second of airtime.