1990 Nichirei International Championships – Singles

In the inaugural edition of the tournament, Mary Joe Fernández won the title by defeating 18-year-old Amy Frazier 3–6, 6–2, 6–3 in the final.

Seeds
The first four seeds received a bye into the second round. • # 🇺🇸 Martina Navratilova (quarterfinals)

• # Monica Seles (quarterfinals)

• # 🇧🇬 Katerina Maleeva (semifinals)

• # 🇺🇸 Mary Joe Fernández (champion)

• # Manuela Maleeva-Fragnière (semifinals)

• # 🇺🇸 Jennifer Capriati (quarterfinals)

• # Helena Suková (quarterfinals)

• # 🇺🇸 Amy Frazier (final)