Deviation in the literary parlance occurs when a speaker or writer deviates from the normal rules and standards of a language. By breaking the rule of language, poets create art from the language that a language group is familiar with. Previous studies on written Igbo poetry (WIP) focused mainly on the content of WIP, with little attention paid to the language of the modern Igbo poets (MIP). Consequently, there is a dearth of research on how deviation occurs in African literatures.  Therefore, through the lenses of Shklovsky’s defamiliarisation theory, this study examines WIP, with a view to describing the techniques used by MIP in achieving deviation, for the purpose of defamiliarising language in their works. Data consists of twenty poems randomly selected from eleven Igbo poetic texts, written between 1975, when WIP debuted to 2015, a period that marks the fourth decade of its existence. The poems studied were subjected to a qualitative analysis that focuses on the use of language to achieve deviation. Findings show that four types of deviation feature in WIP scene: syntactic, lexical, phonological and graphological. Syntactic deviation is achieved through the use of end-weight, focusing and topicalisation. Lexical deviation is the achieved through the use of coinages, lexical borrowing and dialectal deviation. Only apocope phonological deviation feature in WIP, while graphological deviation is done to ease pronunciation with a view to achieving rhythmic effect.