Uhm Ji-won made her acting debut in the late 1990s, and after an early role in the Korean tokusatsu series Vectorman, went on to appear in a number of films and television drama series. In 2004, she appeared alongside Han Suk-kyu and Lee Eun-ju in The Scarlet Letter, receiving a nomination for Best Supporting Actress at the Blue Dragon Film Awards.

In 2005, Uhm played a leading role in Hong Sang-soo’s Tale of Cinema, and was praised for giving an “engaging, emotionally nuanced dual performance” as fictional actress Choi Young-shil. The film required her to perform her first nude scene, and she later remarked that, “After stripping in front of the camera, I felt that I could now take any role.”

Uhm starred alongside Yoo Ji-tae and Kim Ji-soo in the 2006 film Traces of Love, portraying a survivor of the 1995 Sampoong Department Store collapse who still suffers from psychological trauma years later. She prepared for the role by studying news and documentaries of the event, as well as reading through various psychology texts. Uhm was once again nominated for Best Supporting Actress at the Blue Dragon Film Awards and later won the same category at the Chunsa Film Art Awards.