Parliaments are the cornerstone of representative democracy. This chapter examines the role and performance of national parliaments in European democracies. The chapter begins with a review of how parliaments are designed, including the number of chambers and the power of parliamentary committees. It discusses parliaments’ roles and functions, including law-making, government formation, oversight, and political representation, and assesses whether parliaments reflect the make-up of the citizenry at large. The chapter then discusses the possibility of strong parties and dominant executives within the legislative arena leading to weak parliaments, as well as recent attempts to strengthen the capacity of national parliaments.