The movie, which is being produced by Treasure Entertainment, is being billed as Ireland's answer to US blockbuster The Hangover.
Director John Butler says that in terms of gross-out comedy, The Stag will definitely deliver.
The film will be filled with bachelors, stag party antics, nudity and raw eggs.
"Day three filming The Stag," John wrote earlier this week. "Fresco winter nudity, slavering guard dogs and a raw egg."
The cast includes Chocolat actor Hugh O'Conor and Brendan Gleeson. Shooting is currently taking place in Glencree in Wicklow. Threesome actress Amy Huberman will play the part of the laid-back bride in the flick, but at the moments it's very much a 'lads-only' set.
"I won't start for another while," Amy told the Herald. "All the guys have already started filming down the country in the cold and the wet so I'm just leaving them to it," she laughed.
"They don't need me at the moment because they are filming the stag weekend away and obviously, the bride-to-be can't be there."
Amy had worked with John before on Yer Bad Self and said she was thrilled to be working with so many of the same crew.
"It's not exclusively the guys from Yer Bad Self but there is a lot of cross over. It's nice having familiar faces there."