Kang Kek Iew was born in Choyaot village, Kampong Chen subdistrict, Kampong Thom Province, to an ethnic Chinese family who migrated to Cambodia in his father's generation. A star pupil in his school, he passed his "Brevet d'études secondaires de première" in 1961 at the age of nineteen. He finished the first half of his Baccalaureate in 1962 at the Lycée Suravarman II in the town of Siem Reap. The same year he was offered a place in the prestigious Lycée Sisowath in Phnom Penh where he completed his Baccalaureate in mathematics, scoring second in the entire country.