On November 15, 1908, King Leopold II of Belgium formally relinquished personal control of the Congo Free State and the renamed Belgian Congo came under the administration of the Belgian parliament, a system which lasted until independence was granted in 1960.

The Belgian administration might be most charitably characterized as paternalistic colonialism. The educational system was dominated by the Roman Catholic Church and Protestant churches and the curricula reflected Christian and Western values. For example, in 1948 fully 99.6% of educational facilities were controlled by Christian missions. There was little regard for native culture and beliefs. Native schooling was mainly religious and vocational.

Political administration fell under the total and direct control of the mother country; there were no democratic institutions. The head of the state remained the King of Belgium, but day to day operations were carried out by the governor general, who was appointed as a colonial administrator by the parliament.

Native curfews and other restrictions were not unusual. Following World War II some democratic reforms began to be introduced, but these were complicated by ethnic rivalries among the native population.

In the early 1950s Belgium came under increasing pressure to transform the Belgian Congo into a self-governing state. Belgium had ratified article 73 of the United Nations Charter, which advocated self-determination, and both superpowers put pressure on Belgium to reform their Congo policy. The Belgian governments response was largely dismissive. However, Belgian professor Antoine van Bilsen , in 1955, published a treatise called Thirty Year Plan for the Politcal Emancipation of Belgian Africa . The timetable called for gradual emancipation of the Congo over a thirty year period - the time Van Bilsen expected it would take to create an educated elite who could replace the Belgians in positions of power. The Belgian government and many of the évolués were suspicious of the plan — the former because it meant eventually giving up the Congo, and the latter because Belgium would still be ruling Congo for another 3 decades. A group of Catholic évolués responded positively to the plan with a manifesto in a Congolese journal called Conscience Africaine, with their only point of disagreement being the amount of native Congolese participation. The ethnic association ABAKO decided to distance themselves from the plan, in part because most of the Catholic évolués who wrote the Conscience Africaine manifesto were not from the Kongo ethnic group favoured by ABAKO , but also because they had decided to take a more radical, less gradualist approach to ending colonialism. ABAKO demanded immediate self-government for Congo.

The Belgian Congo was one of the major exporters of uranium to the United States during World War II and the Cold War.