Colonialism does not only control the material resources of a country, but it also subjugates people by distorting, disfiguring and destroying the traditional African life. As if it was not enough, racial doctrines became the ideological cornerstone for colonial theories and policies. Racial oppression dehumanizes people, violates and attacks social groups: Blacks and Whites. Tsitsi Dangarembga’s novel The Book of Not is very close to her people and consequently their social realities: what they faced during British imperialism. As a result, this paper aims to show Dangarembga as a social critic who denounces the effects of colonialism and racism in Zimbabwe through the image of Tambu, the main character of The Book of Not.