The aim of this chapter is to provide a general description of the category of discourse markers (DMs) and to propose a functional taxonomy of Persian DMs based on three main categories: interactive, metadiscursive, and connective functions. In contrast to previous studies, a functional approach to DMs offers an overview of the lexical units that have already been analyzed, as well as of other lexical units with similar functions that are still awaiting in-depth studies. Instead of focusing on individual DMs and their polyfunctionality, our focus is on discursive functions. This approach has two advantages: (a) it provides a nonexhaustive list of the main functions fulfilled by DMs, which facilitates the task of describing new units in the future; and (b) it helps researchers who are not familiar with the Persian language to identify DMs on the basis of their functions and find possible equivalents in other languages.