Monthly Film Bulletin said "An extended series of charades, played round a none too substantial comic theme. The plot is left to totter haphazardly from one situation to the next, while Mark Jones zips through from one costume change to the next, displaying commendable physical facility but scarcely one memorable personality amongst all the opportunities provided. When out of drag, he comes across as a close impersonation of
Norman Wisdom." In
The Guardian,
Derek Malcolm wrote: "You would think that with a modicum of talent, the film might either be mildly erotic or passably funny. But, believe me, it is not. Just deeply embarrassing, and deadly dull. If this is what the British film industry is mostly engaged in, the quicker it finally expires the better. It's a terrible sin to make sex so boring."
Time Out wrote: "Screamingly unfunny farce in which a tenth-rate seaside quick-change artist inherits a brothel, and finds himself for some unfathomable reason acting first the part of the recently expired madam, and then that of her clients. Hence the title gag, such as it is. If you miss it the first time round, there's a chorus of voices off and even a theme song to remind you. What with performers who enunciate like rejects from a
RADA elocution course, a script that must have taken all of a weekend to elaborate, a handful of arbitrary flesh shots, and a relentlessly one-note sense of humour (off-key, of course), it is hardly hyperbolic to see
Keep It Up, Jack! as defining a whole new low in British comedy." == References ==