Linguistic scholars agree that both coherence and Cohesion are principal ingredients in the creation of a text. It is safe to say that both concepts have received wide attention regarding the study of a text. As used in this paper, the term text refers to a piece of utterance, be it spoken or written, whose part we put together to form a "unified semantic and syntactic whole" (Babalola, 2013). While the semantic whole refers to a semantic property of discourse, which is based on the interpretation of each sentence vis-a-vis other sentences, the syntactic whole essentially refers to the relations of meaning generated by the agreement of clauses and sentences within a discourse. This paper, in accord with Olowe (1988) and Halliday and Hassan (1976), therefore, centers on Cohesion, which encompasses the relations which is obtainable among the components of discourse (in this case, a piece of a literary text). Emphasis is laid here on cohesive lexical relation in the study of Mariama Ba's iconoclastic masterpiece ? So Long a Letter. The study reveals that the author brilliantly and appropriately deployed the repetitive cohesive devices in her work, making it most successful. Keywords: Repetition, Cohesion, Coherence, Cohesive Device, Mariama Ba, So Long a Letter.