Graham, one of those present at the party, told BBC Newsbeat: “I definitely think I’ve suffered, I’ve had very few partners, and that’s probably because I just didn’t want to put them in an awkward situation.
“It’s made me nervous about being intimate, so I’m not the most confident person when that comes around anyway.”
He said that at school he would get changed away from his friends, avoid urinals in public toilets and even got to the point where he didn’t like leaving the house.
Those in attendance compared length, and some men even walked around completely naked.
It was organised by Ant Smith, 47, who wrote a blog post about having a small penis which went viral.
He told MailOnline: “We got a great cross section of people attending, including guys of all ages and sizes (we surveyed the audience).
“I know there were smaller guys there taking a moment of relief. One gentleman travelled from northern Italy specifically for the party.
“And I heard others talking about how they would never again shout “Small Penis!” when they see particularly bad driving.”
He added: “I do believe, in some small way, The Big Small Penis Party has made the world a little better place.”