Differential Object Marking (DOM) refers to situations in which only a subset of direct objects in a particular language are overtly marked, while others are left unmarked. Presence or absence of DOM is mainly attributed to the semantic properties of the object NP, and it is generally believed that definiteness and animacy are among the main triggers of DOM in languages of the world. However, generally, languages are assumed to differ in two main respects as far as DOM is concerned: They either use different semantic factors in marking of their objects or use different cutoff points when determinant factors are the same. The present chapter demonstrates this phenomenon in Persian and highlights the main triggers for it in Persian in comparison to Armenian. The results illustrate that while in Persian DOM is mainly determined by definiteness of the direct object, it is the interaction between animacy and definiteness that is relevant in Armenian. The research outcomes can also facilitate the teaching of differential object marker to Armenian-speaking learners of Persian.