Occasionally violence is shown but it's mostly mild. One of the main characters, Oz, likes a fight and occasionally beats someone up but it's usually played for laughs. Blood is rarely shown.
In the first series, a man is shown slapping his wife. Neville is also accused of beating up a woman who is shown with a bloody and bruised face in a couple of scenes. Macgowan, who is a thug on the site where the gang work, occasionally beats someone up, including Neville. A fight breaks out in a pub and Oz is slashed with a beer glass and needs a blood transfusion. This happens off screen and he is only shown in hospital with a bruised face.
In the second series, Oz beats up a thug with an headbutt to the nose and stamps on him a couple of times. It's over quickly and only a little blood is shown coming from the man's nose. There is also a big fight between the gang and Ally Fraser's men but it's played out in comical fashion. No blood is ever shown.
In the third series, Oz knocks out a drug dealer with one punch. An hitman is killed by a quick blow to the back of the head. Oz and Dennis have a bar fight with a few red necks.