The film was based on a play The Bull Boys by R. F. Delderfield and was adapted into a script by Norman Hudis with John Antrobus contributing additional material and replacing the conscripted ballet dancers of the novel with a married couple.

He travels to Heathercrest National Service Depot, meeting fellow recruit Horace Strong, a chronic hypochondriac who is devastated at having been passed as fit.

With beady-eyed inspection from Captain Potts and disgruntled support from Corporal Copping, Grimshaw decides to use some psychology and treat his charges kindly rather than simply shouting at them.

They include failure Herbert Brown, upper-class cad Miles Heywood, rock 'n' roller Andy Galloway, delicate flower Peter Golightly and supercilious university graduate James Bailey.

Mary is determined to spend her wedding night with her husband and smuggles herself into the depot to get a job in the NAAFI, a situation Charlie is eventually able to legitimise.

Delderfield's planned screenplay was to have been "one third laughter, one third documentary one third exciting incident leading up to the climax" with the virtues of National Service shown as giving the young men "pride in their regiment and uniform", similar to Carol Reed's 1944 film The Way Ahead.

According to Hudis, "This set the style, to a great extent, of the ones I wrote: the incompetent, the uninterested or the plain unlucky, seen at their worst for most of the story, but triumphing in the end, against all expectation, and to rousing effect.

The movie was financed by Nat Cohen and Stuart Levy at Anglo-Amalgamated who had enjoyed a big success with The Tommy Steele Story also made by Rogers and Hudis.

The title that replaced The Bull Boys was suggested by Stuart Levy to cash in on the popularity of the 1957 film Carry On Admiral, which was written by Val Guest.

[14] Interiors: Exteriors: Variety summarised Carry On Sergeant as a "Corny but mostly very funny Army farce that will click in U.K. provinces, and is not designed for any other type of audience" adding, "A bunch of talented character comedians have been handed these situations and, in their respective styles, they wring a lot more out of them and the dialog than the writers provide.

"[15] The Monthly Film Bulletin called it "a traditionally English mixture of old farcical situations, well-worn jokes, and comic postcard characters.