This paper studies the process of zero derivation in which from a lexeme that belongs to one lexical category, by using metaphoric transfer, a new lexeme is derived, with expanded meaning, with a form changed from inflectional point of view, thus becoming a member of another word class. In this way, the lexeme before and the one after the process belong to different lexical categories, so that zero derivation happens when, as the process requires, nothing derivational is used, but the suffixes which are used for this phenomenon and that are being added, replaced or dropped are of inflectional type. This notion is a characteristic of Macedonian because this Slavic language is rich in inflectional suffixes and that aids the zero derivation, since all the conditions for the process are met: the meaning is expanded, the word class is changed while the form is changed as much as the process allows, that is, only when inflections are used. Of the several types and directions, the paper studies two: from verb (both imperfective and perfective) to noun and vice versa, from noun to verb (imperfective and perfective). Thus, the examples and the analysis will show which inflectional material is used and what the meaning of the new lexeme is, after the process finishes. Therefore, several subtypes of inflectional zero derivation in these two directions will be distinguished, and a metaphoric-cognitive transfer is used to illustrate not only the existence but, more importantly, the productivity of the process in Macedonian. DOI: 10.5901/mjss.2013.v4n3p545