One in 10 people over the age of 50 are at risk of contracting a sexually-transmitted infection because they are not using appropriate contraception, research shows.
A study by Saga found that 10% do not use a condom when they are having sex, and do not know the full details of their partner's sexual history.
The findings, which identified the over-50s as having "frisky" sex lives, formed part of a wider survey into the general health of the age group.
More than 7,800 people were quizzed for the Saga/Populus survey. Of those questioned, 65% said they are sexually active, with 46% of these saying they "get between the sheets at least once a week".
Emma Soames, Saga Magazine editor, said: "These findings shatter the myth that once you hit 50 your sex life is over, there is less pressure than when people were younger and it is likely that you feel more comfortable about your body.
"Forget about the dirty 30s or the naughty 40s. The frisky 50s are having the most fun by swapping the boardroom for the bedroom.
"However, while a healthy sex life is a good thing, the over-50s must be wise to their sexual health, as well as their overall health."