MCKK was closed when the World War II (1940-1945) was fought in Malaya. For another year after the war, the school building was still being used as a military hospital.
MCKK re-opened in 1947 – admissions now opened to all Malay boys, from remote kampungs up to royal palaces. Some were given UMNO scholarship, because Dato’ Onn wanted the college to continue training more Malay boys as future leaders. Headmastter Carey wanted Malays to turn their brains and channel their energy towards science-based subjects so that they could become more science-based professionals rather than art-based land administrators.
After the War, there was a shift in focus for MCKK towards becoming a full-fledge secondary school, to prepare the students for higher education in tertiary institutions- no longer the focus on public service. Curriculum was broader. Nevertheless, MCKK still benefited from its Federal status, which gave special attention for its development. Many of its graduates still entered public and diplomatic services; while others proceeded to become successful professionals in various fields.
Although MCKK was relegated to become just another secondary school after independence, the school continued to carry some of the past traditions established in the first 50 years of its existence. Perhaps, that’s what separates MCKK from other schools in the country.