Parliamentary privilege concerns the powers, privileges and immunities from aspects of the general law conferred on the Houses of Parliament, their members, officers and committees. This paper starts by defining the subject, before looking at parliamentary privilege in the context of a wider constitutional setting, in relation to its underlying purpose, by reference to such doctrines as the separation of powers and the relationship between the courts and Parliament. The second part of the paper looks at outcomes – how the courts have dealt with parliamentary privilege in selected recent cases