The Eve Appeal has called for better awareness of gynaecological cancers among men after it found that 50% of men were unable to correctly identify the vagina when asked to point to it on a diagram.
The charity said that for too many men, women's bodies are "still a taboo subject, shrouded in mystery".
The Eve Appeal's poll of 2,000 Britons - half of whom were men - also found "shockingly" low levels of awareness of symptoms of gynaecological cancers, including cancers of the womb, ovaries, cervix, vagina and vulva.
The survey results, released to coincide with Gynaecological Cancer Awareness Month in September, found that 17% of men said they "know nothing about gynaecological health issues and don't feel that I need to know, as it is a female issue".
And half of men said they would not be comfortable discussing such issues with a female partner.
The charity also raised concerns about female awareness of gynaecological problems.
Almost one in five (19%) women said they would not go to see a doctor if they had abnormal vaginal bleeding - one of the key symptoms across all five gynaecological cancers.
Half of women would not seek help for persistent bloating and 15% would not go to the doctor if they found a lump or growth in their vagina, the poll found.
The Eve Appeal's chief executive, Athena Lamnisos, said: "These survey results show shockingly low levels of awareness of the symptoms of gynaecological cancer among both men and women. For too many men, women's bodies are still a taboo subject, shrouded in mystery.
"We know from the many calls that we receive at The Eve Appeal from men, that they can play a vital role in identifying the symptoms of gynaecological cancer, prompting their partners to visit the GP. Early diagnosis really is key and can save lives.
"'This is not about having better sex. It's about men helping women to look after their health. Gynae awareness and taboo busting are all of our responsibility, men and women alike."
Professor Janice Rymer, vice president of education at the Royal College of Obstetricians and Gynaecologists, added: "Women should never be embarrassed to see a healthcare practitioner if they have concerns about their gynaecological health.
"It is vital to seek help if women experience any unusual vaginal bleeding, change in bowel or urinary habits, pain or discomfort during sex, or unpleasant smelling vaginal discharge. It may be nothing serious, but it's best to get it checked out."
The charity said that more than 21,000 women in the UK are diagnosed with a gynaecological cancer each year.
The Eve Appeal encourages anyone who has experienced possible symptoms of gynaecological cancer - including irregular bleeding; vaginal discharge that smells or may be blood stained; pain during intercourse; changes to the appearance of the skin of the vulva; changes in bowel or urinary habits that lasts for more than a month such as bloating or need to pass water more often than usual - to see their GP.
They can also contact the charity's Ask Eve service on [email protected] or freephone 0808 802 0019.