The survey for YouGov, which polled 1,456 men, found that 68 per cent respondents were unable to identify any signs of prostate cancer.
Even among older men who are most at risk, 62 per cent of men aged 50 to 59 did not know any signs, nor did 60 per cent of 60 to 69-year-olds, and 54 per cent of 70 to 79-year-olds.
Symptoms of prostate cancer include the need to pee more frequently, especially during the night, needing to rush to the toilet, and difficulty in starting to pee or weak urine flow.
Other symptoms include feeling like the bladder has not emptied fully and blood in the urine or semen.
If the cancer has become more advanced, other signs can include bone and back pain, a loss of appetite, testicular pain, and unintentional weight loss.
The poll found that only one in eight men (13 per cent) spotted the most commonly-recognised symptom, which is feeling the need to urinate more frequently.
One in five respondents have had a prostate check with a GP, with men more likely to have an examination as they get older.
However, one in five (18 per cent) of all men say they are “not very” or “not at all” willing to take a prostate check, including six per cent who said they definitely would not have one.
The majority of the men who were polled say they were aware that a healthy diet can reduce the risk of prostate cancer (59 per cent), and that prostate cancer is the most common cancer among men.
But only around a third (35 per cent) of men knew that genetics plays a role. Men are more likely to develop the cancer if a male relative has has also been diagnosed with it.
More than 47,500 cases of prostate cancer are diagnosed each year in the UK, and around 11,500 British men die from it annually.
Amy Rylance, head of improving care at Prostate Cancer UK, said: “Prostate cancer is the most common cancer in men, which makes it especially concerning that most men aren’t aware of some basic facts about the disease.
“However, it’s important to note that prostate cancer doesn’t usually have symptoms until it’s already spread. This means men can’t afford to wait for symptoms before they act and should consider their risk instead.
“Prostate cancer mainly affects men over 50, and the risk is higher for black men or men with a family history of prostate cancer over 45.
“These men should consider speaking to their GP about the pros and cons of a PSA test.”