Cerne Abbas Brewery Ale is on sale in Westminster but the pump clip, featuring the "particularly well-endowed" Cerne Abbas chalk giant, has been covered with a paper fig leaf.
Head brewer Vic Irvine said no-one had taken offence to the logo before.
Parliamentary beer group chairman and MP Andrew Griffiths said his colleagues had "got their knickers in a twist".
The 180ft-tall (55m) giant, cut into the hillside above the Dorset village of Cerne Abbas, is regarded by some as a symbol of fertility.
Mr Griffiths said: "The beer pump has the famous chalk man on the front of it and he is particularly well-endowed.
"That caused some consternation among the authorities here in Parliament and so a photocopy of a fig leaf was Blu-tacked in the strategic place.
"I think honourable members have got their knickers in a twist, but I hope as a result of it they drink a bit more beer."
Mr Irvine said: "We all live in the shadow of the giant. We celebrate him on May Day, we're up at sunrise, and we celebrate the fertility.
"Jodie and Chris who I work with have both become fathers within a month of each other and the brew wasn't even 15 months old at the time so I think there's quite a lot in it, so to see the fig leaf is quite funny really."
The ale is one of several guest beers available on rotation in Parliament's Strangers' Bar.
Mr Irvine said it was not clear whether the fig leaf would be reattached when the next barrel went on sale.
A brewery's logo has been censored in a Houses of Parliament bar because it was deemed too shocking.