This article presents a proposal for the organization of the Contextual Component in Functional Discourse Grammar. A guiding principle in this proposal is that, given the fact that Functional Discourse Grammar is a theory of grammar, the Contextual Component should provide the information that is necessary for a proper functioning of the grammar rather than aim at an exhaustive specification of all the information that plays a role in interpreting linguistic expressions. The Contextual Component contains situational and discursive information and is organized in different strata that correspond to the interpersonal, representational, morphosyntactic, and phonological levels of representation within the grammar. The contextual representations make use of the same formalizations as the corresponding linguistic representations, thus allowing for direct exchange of information between the Grammatical and the Contextual Components. Thus exchange of information is handled by an interface called the contextualizer. The article illustrates the functioning of this model by analyzing the role of contextual information with respect to three grammatical phenomena in three different languages: Unexpressed arguments in Turkish, English too, and answers to yes/no questions in European Portuguese.