By 15 November 2004, all candidates had submitted their candidature files to the IOC. After a period of analysis by the IOC, the cities were visited by the IOC Evaluation Commission, consisting of twelve members and chaired by Moroccan IOC member Nawal El Moutawakel. The four-day visits occurred between 3 February and 17 March 2005:
- Madrid — February 3–6
- London — February 16–19
- New York City — February 21–24
- Paris — March 9–12
- Moscow — March 14–17
The Parisian bid suffered two setbacks during the inspection: a number of strikes and demonstrations coincided with the visit, and a report was released stating that Guy Drut, IOC member and one of the key members of Paris's bid team, would face charges over alleged political party financial corruption.
On 6 June 2005, the IOC released the inspection team's evaluation reports of the five candidate cities. Although these documents did not contain scores or rankings, the report for Paris was considered the most positive, followed closely by London, which had narrowed most of the gap observed at the time of the first-phase evaluation in 2004. New York City and Madrid also obtained very positive evaluations, while Moscow was considered the weakest bid. On the same day, New York City's bid suffered a major setback following the report that the State of New York refused to fund West Side Stadium, a New York 2012 centrepiece. The New York City campaign devised an alternative plan within a week, but such a major change with only one month remaining before the final vote damaged the city's chances.
Throughout the bidding process and leading up to the vote at the 117th IOC Session, Paris was widely seen as the favourite, particularly as its bid was the city's third in recent history (previous bids being for 1992 and 2008). London was originally seen as lagging behind Paris by a considerable margin, but this situation began to reverse with the appointment of Sebastian Coe as the head of London 2012, on 19 May 2004. In late August 2004, reports emerged that predicted a tie between London and Paris. In the final run-up to the 117th IOC Session, London and Paris appeared to be in an increasingly close contest. On 1 July 2005, IOC president Jacques Rogge, when asked who the winner would be, told the assembled press, "I cannot predict it since I don't know how the IOC members will vote. But my gut feeling tells me that it will be very close. Perhaps it will come down to a difference of say ten votes, or maybe less.