Political parties are considered to be vital elements of political life in modern democracies, and whether in democratic regimes they maintain democratic mechanisms within their own organizations and structures has been an intriguing topic. The most important issue is which factors influence the internal democracy in parties. This article examines the relationship between functioning of democracy in parties and party leadership, candidate selection mechanisms, membership systems, policy formulation systems and communication channels. In addition to the commonly used indicators of intra-party democracy in three areas – the leader’s power and control, nomination process and determining policy preferences – this article deals with the process of membership recruitment and membership rights. It analyses the factors that influence intra-party democracy in Turkey focusing on the multiparty period after 1946 by giving examples from the political parties and previous research results.