The purpose of this essay is to describe and analyse the current law that refers to extra- occupational activities. An extra-occupational activity is defined as any employment, assignment or other activity that an employee engages in apart from his or her principal employment. We are in this essay carrying out an external comparative study, by comparing Denmark’s and Great Britain’s regulations regarding extra occupational activities. We have chosen these countries because they represent two different legal systems (families), the Romano- Germanic and the Anglo-Saxon (Common Law). An internal comparative study is also carried out in the essay. By presenting an account of three different kinds of not allowed extra- occupational activities: those who adversely affect confidence, those who adversely affect working practices and those who are competitive by nature. We are comparing within the Swedish regulations - which include regulation by statue, agreement and established practice- employment in the public sector; the state, the municipalities with the employed in the private sector.