This thesis seeks to clarify the root causes of anti-Islam attitudes in predominantly Christian Rwanda. First it focuses on the thinking of the first missionaries (White fathers) in their enterprise of sheer rejection of both Islam and Rwandan Traditional Religion. Surprisingly, the influence of Rwandan Traditional Religion on the two other faiths remains significant. Second, it reviews the role played by Western missionaries in reinforcing anti-Islam attitudes in connection with their struggles against Arab slave trade in East Africa in the second half of 19th century. It is necessary to revisit the violent, often hidden history of Christianity, Islam and their relations in Rwanda; after mass atrocities, it is also necessary to undertake a reconciliation of memories. The commemoration of tragedy and suffering informed by reconciliation of memories may be a significant contribution to the healing of the nation and may at the same time contribute for preventing religion-based violence.