The highly ambiguous structure of the Persian Noun Phrase (NP) causes immense difficulties for automatic parsing of written text. Factors contributing to the ambiguity of the Persian NP structure include the lack of overt morphology to mark boundaries, the fact that short vowels are not written in Persian text, a relatively free word order and the optionality of the subject. This paper introduces the constituents forming a Noun Phrase in Persian. The syntax of NPs and relative clauses is described. A closer study of the Noun Phrase provides lexical and morphological clues for determining boundaries. To describe the NP rules in the Shiraz machine translation project, developed at CRL, a unification-based syntactic grammar was used, which operates on typed feature structures.