Nigerian politics and practice have a mixed history, and despite its apparent openness to the general public, it remains a mystery and opaque to the outsider. This paper examined the phenomenon of Political Parties and the Practice of Internal Democracy in Nigeria’s Fourth Republic with special focus to the People's Democratic Party (PDP) and the All Progressive Congress (APC). The paper relied on secondary sources of data as its primary source of information. This strategy is used because of its inherent benefits. To be specific newspapers, periodicals, textbooks, the internet, journals, government publications, official documents, and other secondary sources were used in this study to give insight into party politics and internal democracy. This study used content analysis method of investigation and analysis. This entails deciphering the meaning of materials gathered in order to arrive at a credible and verifiable conclusion. The research found out the political parties in Nigeria lacked much-needed internal democracy, particularly when it comes to candidate selection. Political incumbents and so-called godfathers were also characterized as having an arrogant and demanding attitude. The paper therefore, suggested amongst others that political parties must be revamped to allow voters to freely elect those who represent them and fight for leadership positions. To maintain the democratic ideals of consolidation such as tolerance, accountability, and transparency, effective institutions should be established.In addition, social capital culture must be infused into Nigeria's political system. Without social capital, any institution or organization may struggle to function at its full potential. Keywords: Politics, Political parties, Democracy, Internal democracy.