Poetic language, which constitutes one of the subcategories of literary language, differs from both daily and scientific language. One of the distincttive characteristics that distinguishes it from both daily and scientific language use is linguistic deviation. All uses that go beyond the rules of the standard language constitute language deviationLinguistic deviation has a significant impact on the acceptance of poetry as a metalanguage. Reacting to the strict rules of the standard language, poets try to eliminate their aesthetic concerns and make what they say effective by making changes to the language. Linguistic deviations, which can be examined in nine classes: orthographic, verbal, phonetic, semantic, grammatical, historical, dialectal, segmental and interference with borrowed texts, make their existence visible especially in the last periods of Turkish poetry. İhsan Deniz, who managed to make a name for himself with the poetry books he published in the 1980s, is one of the most remarkable artists who benefit from linguistic deviations. Deniz, who collected all his poems in the book called Dut Ağacı, uses examples suitable foro other types of deviation except historical deviation ih the poet’s poems were examined under eight headings. In the study, before this classification, theoretical information was given about language deviations. The poet’s work titled Dut Ağacı, which collects his poems written between 1980 and 2015, was chosen as the sample for the study.