It’s apparent that the creative team was struggling as this blend of "Carry on Nurse" and "Carry on Doctor" appeared. This time, Sid James isn't among those receiving treatment; he portrays “Carter,” who is boldly scheming to steal valuable drugs from the "Finisham" hospital. To aid in his plan, he believes his son, "Cyril" (Kenneth Cope), should dress as a nurse and pretend to be one so he can learn the layout before they commit their theft. Meanwhile, “Dr. Prodd” (Terry Scott) is cast as the wandering, clumsy doctor, Hattie Jacques plays a matron who isn’t quite as severe, and Joan Sims really shines as "Mrs. Tiday," who seems content to consume everything while her railwayman husband (Kenneth Connor) gets visibly older and more annoyed in the waiting area. Occasionally, elements of the classic slapstick humor surface; the script has moments of genuine amusement, and there are numerous opportunities for laughter with the “how's your father” jokes – whether they’re truthful or not. It isn't a standout film, nor even close, but it offers a good deal to enjoy until the conclusion, which certainly suggests another installment is in the works.

Source on TMDB