In August 1988, Nakhirunkanok was presented the Thai Royal Medal of Honour, Most Exalted Order of the White Elephant, by King Bhumibol Adulyadej for her service in helping children in need.
Aged 19, Simon was crowned as Miss Universe 1988 by outgoing titleholder Cecilia Bolocco on May 24, 1988, in Taipei, Taiwan.
She became the second Thai woman to win the title after Apasra Hongsakula who won Miss Universe 1965.
[4] Simon became the first woman ever to win both the Miss Universe and Best National Costume award in one pageant.
[4] Simon crowned her successor, Angela Visser of the Netherlands, at Miss Universe 1989 in Cancun, Mexico.