1990 MSSU softball teams finished fourth in the NCAA World Series and went 36-9 overall. The team was coached by MSSU Hall of Famer Pat Lipira.

The 1990 team helped usher in the NCAA era for Missouri Southern and the team didn't disappoint, earning an NCAA Regional Championship and a trip to the NCAA Division II World Series in the first year as a member of the NCAA. The Lions won the MIAA Tournament with a win over Missouri – Rolla (Missouri S&T) and took the title in the NCAA Midwest Region Championship with a win over Florida Southern.

Diane (Dink) Miller was named a second-team All-American as a catcher. Miller was also named the team's Outstanding Offensive Player, the Female Student-Athlete of the Year for the Lions and was a first-team All-Region selection. She became the second sophomore Lion to be named an All-American.

Miller's 15 doubles that season ranks seventh-best in a single-season at MSSU, while Monica Fabro's 21 sacrifice hits rank seventh in a single-season. Deanna Combs has the fourth-highest winning percentage in a single-season for a pitcher as she went 22-4 in the circle that year.

Jennifer Burken was named to the Final Four All-Tournament team. Deanna Combs, Kim Pellow, Fabro, Leslie Myers, Carrie Carter, and Tiffany Carter was named onto the South Region All-Tournament team and Combs was named the tournament's outstanding player. Combs and Miller were named first-team All-Region, Carrie Carter was named onto the second-team and Lipira was named the Regional Coach of the Year.

Lipira was named the MIAA Coach of the Year, Miller was the Most Valuable Player in the MIAA, while Burken, Carter, pitcher Combs and Robin Herschbach were named first-team All-MIAA, helping the Lions to win their first MIAA tournament championship.