The aim of carrying out of this research was Discourse-Grammatical analysis of Sohrab Sepehri's poem: 'Sedaye Paye Aab' on the basis of the methodology expounded by Halliday (1976), Shafaie (1984), and Farsheed Verd (1984). While utilizing the method of text analysis, the said poem has been examined at two levels, namely: macro and micro levels. The macro level pertained to the identification of cohesive devices, while the micro level dealt with the types of sentences which were used in the said poem. The findings revealed that the referral cohesive device (399 cases, 49.62%) had the highest frequency in the entire poem. It is followed by the lexical, deleted and conjunctive devices having 27.49%, 11.82% and 11.07% respectively. They stood at the subsequent positions. At the same time it was made clear that the poet has made more use of referral devices like pronouns and verbal adjunctives (353 cases, 88.47%) and additive–conjunctive devices (96 cases, 86.49%) than the other kinds of references and conjunction devices. Amongst lexical cohesive elements and repetition also (185 cases, 83.71%) had the highest frequency. At the micro level, no traces of passive and conditional sentences were found. At the same time, it became clear that the writer has used active, declarative, simple, and verbal sentences as compared to other types of sentences.