Kao was born in the village of Ban Nam Nhom, province of Xiengkhouang, Laos. He attended the College of Lycee de Vientiane, Laos, and honorably graduated with a Bachelor’s Degree in Mathematics. Kao enrolled in the Military Cadets School of the National Royal Lao Army at Fort Phonekheng in Vientiane, Laos. Subsequently in August 1974, as a scholar, he received a prestigious scholarship to attend the French Army Officers School in Lyon, France. He successfully completed his military studies/training and graduated with the rank of a French Lieutenant Officer in 1977. Kao was a teacher in French National Education and taught French to diverse migrants. He also worked for the Technique & Vulgarisation Company and Transportation for Tourism as a manager in Paris. Kao, his wife, and a son recently migrated to Milwaukee, Wisconsin to be closer to his brothers, sisters, and friends while operating his own business.