Rosati-Kain is accredited as a college preparatory school by the North Central Association, the Missouri Department of Education, and the Roman Catholic Archdiocese of Saint Louis.

In 1921, the Hayes Mansion was moved to make room to build a new larger structure designed by architect Henry P. Hess.

The 2011-12 school year marked the 100th anniversary of Rosati-Kain, and the institution held a year-long Centennial Celebration at that time.

A new school song was written specifically for the Centennial Celebration by faculty members Luanne Murphy and Laura Govero-Yann.

[4] In 2009, BusinessWeek Magazine and GreatSchools.net named Rosati-Kain the Top Parents' Choice Private High School in the state of Missouri.