Chiu ran as an independent legislative candidate representing Taipei in 1992. After she joined the Democratic Progressive Party in 1997, Chiu ran for a legislative sat in Pingtung County the next year. She was placed on the party list for the 2001 legislative elections and won a seat via proportional representation. As a candidate, Chiu expressed support for actress to join her on the party list. Chiu also backed the establishment of a red light district in Taiwan. Prior to taking office in February 2002, Chiu criticized the DPP's legislative organizational structure, and the regulations regarding election to the speakership. Internal edicts decreed that elections for positions within the legislature were to take place via secret ballot, but for the 2002 speakership election, the Democratic ProgressiveParty caucus resolved to "technically display" their ballot. Chiu did not do so for the vice speakership election, and was expelled from the Democratic Progressive Party for violating party rules in April. She described the decision as "political assassination." An impartial arbitration committee overturned the expulsion, but the party caucus voted in May to censure Chiu. As a result, Chiu's case was again heard by the DPP's Central Review Committee, which voted to expel her for a second time. Lin Wen-lang was selected to assume Chiu's vacant legislative seat in June. Chiu petitioned the Council of Grand Justices to rule on the party's decision, but the council stated, "It is up to individual parties to decide what they should do with members who fail to obey internal rules," and dismissed her petition.
Later career
After leaving the legislature, Chiu returned to her legal career. In August 2002, she represented Cheng Yu-cheng, a legislator who left Taiwan for the United States and filed for divorce from his wife. In 2010, she represented users of Ortho Evera, in a transnational class action lawsuit. In 2018, she commented on legal matters regarding the actors, Di Ying, and their son, who was suspected of planning a shooting in Upper Darby, Pennsylvania, where he was attending school. In 2019, she discussed Terry Gou's candidacy in the Kuomintang presidential primary.