Kyrgyz lawmakers, diplomats and the president of neighboring Kazakhstan, Nursultan Nazarbayev, attended the ceremony, which took place at the House of Government in the capital, Bishkek.
Last week, the election commission said President Bakiyev won 76 percent of the vote, while his closest challenger, opposition candidate Almazbek Atambayev, was far behind with 8.4 percent of the vote.
The opposition accused the government of rigging the vote, and it organized anti-government demonstrations.
The Organization for Security and Cooperation in Europe (OSCE) said the elections were marred by widespread irregularities to ensure a Bakiyev victory.
The OSCE said its monitors noted incidents of ballot box stuffing, multiple voting and even vote buying, and it concluded that the polls did not meet "key international standards."
Agencies