This study attempts to linguistically unveil the cohesive devices in Thiong'o's novel "A Grain of Wheat" (1967). It attempts to explicate the points that relate the novel via adopting the theoretical framework of Halliday and Hasan (1976) model of cohesion. Through a close linguistic analysis of the novel in terms of diction, allusion and other aspects in which the novel relate, it is clear that the author uses cohesive devices in the composition of his literary text. The writer uses of his historical background and life experiences as foregrounds in portraying the realities faced by his main characters in the novel. The study adopts a qualitative approach and identified the use of grammatical cohesion which consists of reference, substitution, ellipsis, and conjunction, and lexical cohesion which includes reiteration and collocation. Then, the researcher outlines the number of instances, the cohesive items in data sheets. The study accounts for frequencies of occurring types of cohesion. The result shows the frequencies occurrency of the devices in order to provide the details. The study argues that the author is linguistically successful in constructing the ideas of colonialism and racial discrimination. An awareness of the continued inequalities experienced by the black race in relation to color. Racism and colonialism needs to be voiced out. Hence, this study contributes to existing issues on the construction of racism and colonialism. The study, therefore, has achieved its objective and proved the hypotheses. "Cohesion" in Afican narratives has added a new dimension to know more about the ideas of colonialism and racial discrimination.