The How I met Your Mother star joined Deschanel onstage at the Rape Foundation's yearly brunch in Beverly Hills, California, to honour the organisation's work.
Deschanel later took to Twitter.com to praise the charity, which offers programs and services to rape victims of all ages, writing, "Honored to be at brunch for the rape treatment center and Stuart house today. They do Such incredible work!"
Radnor adds, "Hosted the Rape Foundation brunch with Emily Deschanel today. An incredible organization doing incredible work."
The event was also attended by U.S. Tv stars Christina Hendricks and Eric MCCormack.