The 71-year-old leader has ruled the largely Muslim nation for three decades, becoming Asia's longest-serving president. Gayoom has been president for six terms under the country's single candidate system.
However, this time around he faced a serious threat from human rights activist, Mohamed "Anni" Nasheed, founder of the Maldivian Democratic Party and a former Amnesty International prisoner of conscience, Britain's Guardian reported.
Gayoom faced four other opponents in the elections, which come at the end of peaceful democracy campaign following violent riots in 2005.
Security remained tight on the nearly 1,200-island archipelago with a population of 300,000 and whose main industry is tourism.
But under the supervision of international observers, voting proceeded smoothly expect for some complaints of polling irregularities, the report said.
Election results are expected Thursday.