She was discovered by Seiko Films when she was 15 years of age soon after applying for work in Japan. She then started on sexy roles on various films by Seiko. In October 2002, Zubiri became widely known in the Philippines after posing on the EDSA-Shaw flyover in Mandaluyong City. In 2005, Zubiri moved away from sexy films and focused on becoming a TV actress on the GMA Network. One of her notable roles was portraying Danaya in the Encantadia fantasy series.
She was also a regular cast in the sketch-comedy program, Bubble Gang and starred on drama series like Babangon Ako't Dudurugin Kita and Danny Zialcita's Gaano Kadalas Ang Minsan?.
Zubiri, when she was at about eight years old, together with her elder sister were left in the sole care of their mother when her father left them at Olongapo City. The family later transferred to a rented home in Fairview, Quezon City, where Diana spent her child life. Zubiri was a member of the Iglesia ni Cristo but converted to Roman Catholicism during her early years in showbiz. She is now studying at MIRIAM COLLEGE and is at present not so active in her showbiz career.