Of these men, 46 also agreed to have their manhood measured while both flaccid and erect.
They found 30 per cent of the men were unhappy with their genitals, while 35 per cent were content.
The rest said they fell somewhere between happy and unhappy.
The results showed that older men and gay men were more likely to experience penis anxiety.
The penises measured during the study ranged in size from seven to 18cm when flaccid but stretched.
When erect, they ranged from 10 to 20cm long.
In terms of girth, the flaccid penises ranged from seven to 13cm while the erect ones ranged from nine to 17cm.
Dr Veale said the most surprising finding was that many men said they feared other people being able to work out the size of their penis when they were wearing trousers.
Dr Veale believes that the level of a man's penis size anxiety is more likely to be determined by their experiences than by their actual size.
"Quite a few of them have been teased about their size either by an ex-partner or in the showers as an adolescent," he said.
- DAILY MAIL