In 1929, Hans Kelsen published a relatively slim book named On the Essence and Value of Democracy. Surprisingly, only a few segments of it were translated into English. One of the underlying theories elaborated by Kelsen is the need for political parties. Kelsen outlines the main justifications for the existence of political parties as derived from the concepts of liberty, equality, and representation. He concludes that political parties are essential for a modern democracy, and thus the modern state should be a party-state (parteienstaat). The goal of this Article is to outline Kelsen's theory on political parties and understand its historical and theoretical background. Furthermore, it strives to evaluate the relevance of Kelsen's theory on political parties nowadays. Kelsen's work is confronted thus with different parties malfunctioning such as non democratic and self interested parties. Reviewing Kelsen's work, there are also doubts about the proper constitutional status of political parties. Furthermore, there are some interesting possible observations regarding Kelsen's suggestion to recall a representative who shows disloyalty to the party line. This Article will demonstrate that Kelsen's work on political parties was not only innovative, but that it is also relevant to any modern debate about the constitutional status of political parties.