Unlike contemporaneous 1970s sitcoms such as Dad's Army, Porridge and The Good Life, the BBC does not show repeats of It Ain't Half Hot Mum, allegedly due to its politically incorrect content, which is regarded as badly dated. Before his death, writer Jimmy Perry criticised this, saying the series represents "the historical truth" and helps people understand an important part of history and the changes which came about. He said the BBC was "taking the cowardly way out" by not showing it.
In 1975, co-stars Windsor Davies and Don Estelle topped the UK charts with the novelty song "Whispering Grass", which they performed as their characters from the series.
Some critics viewed the casting of the white actor Michael Bates as the Indian bearer Rangi Ram as an example of blackface, "All Michael Bates wore was a light tan", protested Jimmy Perry in a 2013 interview with the journalist Neil Clark, an admirer of the series. In Clark's opinion, the series "delightfully lampooned the attitudes of the British in India", but is "wrongly attacked by the PC brigade for being racist and homophobic". Such a perception, however, is believed to be at least partly responsible for the programme not being repeated on British television in later years, along with, according to Darren Lee of the British Film Institute's ScreenOnline website, a belief it contains "national stereotyping and occasionally patronizing humor". According to Mark Duguid, writing for the same website, it suffers "from its narrow stereotypes of its handful of Indian supporting characters as alternately servile, foolish, lazy or devious". Its flaws have not stopped it appearing in several "best of" lists. The show's producers had been aware the issues around the casting a white actor to play one of the Indian characters, but relented owing to the lack of suitable Indian actors at the time. Jimmy Perry defended the casting as Bates "spoke fluent Urdu, and was a captain in the Gurkhas".
Leonard Rossiter originally auditioned for the part of Sergeant Major Williams, but was rejected by creators Jimmy Perry and David Croft because he arrogantly demanded that his part be re-written to match his own views of how he saw the character.