This paper examines the stress system of Persian with particular attention to phrasal stress. Contrary to the long-held belief that Persian stress assignment is sensitive to lexical category, it is argued that the word-final stress rule applies to all verbs, as well as nouns and adjectives. Working in a Phrasal Phonology framework, I show that the superficial uniformity of stress placement in nouns and the variability in verbs follows from an appropriate understanding of the different syntax of these categories along with mapping to prosodic structure. Several complex constructions are also examined and it is shown that their unusual behavior with respect to stress can be explained in a straightforward manner through the prosodic hierarchy if their syntactic structures are taken into account and different edge settings are allowed at different levels of the prosodic hierarchy.