Internal party democracy is an important feature for radical left parties. Despite its ideological diversity this party family emphasises democracy in its decision-making be that in the form of a top-down democratic centralism or a bottom-up, grassroots inputs towards policy formation and candidate selection, among others. Recent years saw these parties experimenting with their organizational features in order to engage their members and to improve their linkages with non-party organisations, such as social movements, trade unions, or formal and informal collectives. This paper investigates what are the contemporary deliberative practices of radical left parties in light of these organizational changes. Basis for this analysis will be a comparative case study of four radical left parties that differ ideologically and organisationally: Die Linke (Germany), Levica (Slovenia), and the Worker’s Party of Belgium, and the Communist Part of Bohemia and Moravia (Czechia). Using documentary analysis of party documents (programs, statutes, congress proceedings, etc.) and media reports on these parties will reveal the diverse deliberative practices of radical left parties and outline factors for this diversity.