As an amateur in 2003, she won a professional event on the LPGA of Japan Tour, the Dunlop Ladies Open, in Miyagi Prefecture where she was attending high school at the time.

At the LPGA Qualifying Tournament in Florida in December 2005, Miyazato easily secured her tour card for the 2006 season.

In Miyazato’s fourth season on the LPGA Tour in 2009, she earned her first win at the Evian Masters in France, defeating Sophie Gustafson at the first hole of a sudden-death playoff.

[3] In 2010, Miyazato won four of the first nine official tournaments on the LPGA Tour and on 21 June rose to number 1 in the Women's World Golf Rankings.

[4] In August, Miyazato won for the fifth time in 2010 at the Safeway Classic in Oregon, with a two-stroke victory over Kerr and Na Yeon Choi.

The LET has no minimum tournament requirements for membership and her second win at the Evian Masters, whose purse is much larger than most LET events, earned her enough to top the list.

Miyazato has endorsements deals with Suntory, Bridgestone Corporation, Japan Airlines, Oakley, Honda, Hisamitsu, Mitsubishi Electric and NTT Docomo.