[9] During her reign, Díaz travelled through several countries to promote the advocacies supported by the Miss Universe Organization as well as appeared in many public and television events in the United States.

Shortly after her reign as Miss Universe ended, she pursued an acting career in the Philippines, and in 1975, she was cast in her breakthrough performance as Isabel in the critically acclaimed Ang Pinakamagandang Hayop sa Balat ng Lupa.

In 2006, Díaz was cast in the psychological thriller Nasaan Ka Man alongside award-winning actress Hilda Koronel, Claudine Barretto, Diether Ocampo and Jericho Rosales.

For her role as Lilia, a woman trying to suppress her distraught as she tries to keep her family together, Díaz was once again nominated and eventually awarded as FAMAS Best Supporting Actress.

[citation needed] In 2019, Díaz returned to ABS-CBN and was recently cast in the afternoon drama series Los Bastardos where she portrayed the role of Soledad Cardinal, the long-lost wife of Don Roman Cardinal (Ronaldo Valdez), and Consuelo Cuevas, the mother of Lorenzo Cuevas (Joseph Marco).

She also appeared as a fictional version of herself in the second season of the Netflix series Insatiable with Dallas Roberts and Debby Ryan.

[16] In a TV Patrol interview shortly after the Miss Universe 2010 pageant on August 23, Díaz commented on Binibining Pilipinas contestant Venus Raj becoming 4th runner-up.

"[17]Her remark sparked outrage amongst many Cebuanos, who felt that Díaz insulted their English proficiency by championing the controversial issue of Tagalog imperialist culture in the Philippines.

Cebuano politicians such as Cebu Governor Gwendolyn Garcia and Congresswoman Rachel del Mar called on her to apologise.

That's what I said and that's what I meant.On September 1, 2010, the Vice Mayors' League of the Philippines-Cebu passed a resolution declaring Díaz a persona non grata within Cebu City.