President S. R. Nathan, who earlier gave indications of a retirement, decided a month before this election to run for another term. Once again, as the only candidate with a Certificate of Eligibility, he won uncontested for the second time.

Four other candidates were denied the COE, including 2001 General Election independent candidate Ooi Boon Ewe. He was one of the two who also failed to qualify for the 1999 Presidential Election.

The most controversial unsuccessful applicant was Andrew Kuan, a former PAP member and chief financial officer of Jurong Town Corporation. After Prime Minister Lee Hsien Loong called on those acquainted with Kuan to speak freely on what they knew about him, his former boss, JTC chief executive officer Chong Lit Cheong, held a press conference to expose him as a poor performer who was asked to resign. Kuan disputed this, saying he received a raise and bonus during his service.

In the end, the Presidential Elections Committee ruled that Kuan did not qualify, as the legal requirement specified that an eligible candidate had to serve as a chairman or CEO, not a CFO, for at least three years.

This election marked the first time an incumbent elected President ran for a second term in office. Due to the no-contest, polling day scheduled for 27 August 2005, with overseas voting decreed for the first time in Singapore history, did not take place.