Cashing in on the wave of Carry On euphoria in the late sixties, and falling back on their most successful setting - hospitals - Carry On Again Doctor once more casts Jim Dale as the young, lively, honest, and clumsy doctor that he first introduced in Carry On Doctor two years previously. This time he plays Dr Nookey, whose eye for the ladies is bound to get him in trouble with his boss, Dr Frederick Carver (played as only Kenneth Williams could play him).
And sure enough, after a series of blunders, caused by his relentless pursuit of Barbara Windsor's Goldie Locks, Dr Nookey is shipped off to a hospital mission on the inappropriately named Beatific Islands.
This gets him nicely out of the way for Dr Carver, whose aim is to screw.... some money out of Ellen More (Joan Sims), a wealthy widow with, shall we say somewhat generous tendencies and an eye for a new partner. Carver wants to set up a private clinic, but needs money to do it.
Meanwhile, back on The Beatific Islands, it hasn't stopped raining, the one jigsaw puzzle on the island has a missing piece, and the scotch has run out. But there turns out to be a surprise bonus, in the shape of Gladstone Screwer (Sid James), and his miracle weight loss formula. Armed with this wonder-serum, Dr Nookey returns to England, sets up his own private clinic, and successfully recruits Ellen More to help finance the operation.
This upsets a few people, of course. Dr Carver, with the assistance of psychiatrist Dr Stoppidge (Charles Hawtrey) tries all he can to discover the secret formula, including planting a 'woman' in the female-only clinic, and Gladstone Screwer, who works out that the 200 cigarettes a bottle he gets paid for the serum might not be enough, and decides to travel to England on a little visit.....
This movie, like the others in the series, has great performances, a wonderful script, and some really funny lines. Cameo performances abound, most notable from Peter Butterworth, whose response when Dr Nookey and a colleague have a bet on a 'spot-analysis' on his condition is magical.