The BBC launched an investigation after a listener complained that Samantha - the imaginary scorer on long-running Radio 4 comedy show I'm Sorry I Haven't a Clue - was being treated as "a sexual object".
The programme, which has run for more than 40 years, features comics including Jack Dee and Barry Cryer who regularly refer to the fictional "lovely Samantha".
The listener complained about two episodes in July last year which she said included "highly sexist, offensive and harmful" references to the character.
A BBC Trust report said: "She considered that Samantha was only referred to as a sexual object and believed the male panellists used 'schoolboy sexist so-called humour', that was 'both puerile and unfunny'."
The report referred to examples of innuendo included on the show, including a description of the character as "a lovely lady who's scored on more desks than she can remember".
In one episode, listeners were told that Samantha was going to the cinema with two men who were fans of horror films because "she enjoys nothing better than sitting in the back row and being given the willies for 90 minutes".
The programme was defended by its producer, who said using innuendo was "part of the programme's tradition of wordplay and punning" and was appreciated by "the vast majority of listeners".
The listener took her complaint to the BBC Trust and quoted a United Nations Special Rapporteur on Violence Against Women who said the UK had a "boys' club sexist culture".
She also got in touch with the producer who told her the show would book more female panellists and feature Sven, described as the "male equivalent of Samantha", more often.
It would also be made clear that Samantha was "often the initiator in these relationships to avoid the suggestion that she was being taken advantage of".
The Trust's Editorial Standards Committee said it "could understand why some listeners believed that this type of humour was outdated", but said "the majority of listeners were familiar with the content of the show and enjoyed the wordplay associated with the innuendo".